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National Institute for Materials Science

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[FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274 Physics and Chemistry of Functionally Graded Materials Research Report (pp.237-474)](https://mdr.nims.go.jp/datasets/258566e5-2ef2-42e9-b3f5-6be640868208)

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Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 237-242 選択的還元によって傾斜機能を持たせた高光歪セラミックスの開発 Functionally Graded High Photorestrictive Ceramics by Preferential Reduction 野間竜男　和田智志東京農工大学工学部 Tatsuo Noma , Satoshi WadaDepartment of Applied Chemistry, Tokyo University of Agriculture and Technology  One of the unique properties seen in ferroelectric ceramics is the photoristrictive effect. This is a combination of the photovoltalic effect (transformation of light energy to electric energy) and the piezoelectric effect (transformation of electric energy to mechanical energy). It is expected to apply such direct transformation of light energy to mechanical energy to photodriven motors and relays, etc.. There are three important obstructions to be overcome in order to achieve practical application:      1) the driving wavelength is limited to the ultraviolet range (360nm)     2) the strain is small (1x10 to the -4th power)     3) the response is slow (1 sec ~)     The authors have successfully broadened the driving wavelength up to 380nm by substituting the rare earth trivalent ions in PLZT.  This is not long enough if laser beams are to be used as driving waves, but the first one of the aforementioned problems is in sight.      A piezoelectric material called RAINBOW (Reduced And Internally Biased Oxide Wafer) ceramics have recently been attracting much attention. A RAINBOW ceramic is fabricated through a preferential reduction by heat treating a ferroelectric ceramic (in the form of a wafer) containing lead, such as PZT, with a graphite plate on the either surface in an oxidizing atmosphere. Only one side of the wafer is reduced to form a "graded structure" across the thickness.      In the present work, to solve problems 2) and 3), we proposed a preferential reduction of PLZT photoristrictive ceramics to be carried out to: A) Improve the electric-to-mechanical energy conversion performance by increasing the electromechanical coupling coefficient and thermal strain and to B) Improve the light-to-electric energy conversion performance, especially the response speed, by adding a graded electric conductivity. Also we examined what conditions of graded profile of electroconductivity (or ferroelectric-conductor) are needed for the optimization of energy conversion function.     The aim is to improve optoelectric energy conversion performance of ferroelectric ceramics by adding the graded function of ferroelectric-conductor and to develop an improved photoristrictive actuator that shows a high strain and a quick response.     As a preliminary step, we focused on the processing of PLZT-PZT functionally graded materials and their property evaluation. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 243-248 複合積層化合物を利用した電気・磁気傾斜機能材料の開発と物性 Preparation and Properties of Electrically and Magnetically Graded Materials using Composite Layer Compounds 鈴木和也横浜国立大学工学研究科 Kazuya SuzukiYokohama National University Graduate School of Engineering  Investigation of bonding strength and interactions between different atomic layers along with the quantum effects that might appear in ultimately thin layers, is important not only from the physical point of view but also with a view to future applications. Chemical compounds that have alternate stacking structure and that which can easily change the type of atomic layer are best suited for such studies on the fundamental properties. In this study, we will use a new type of alternate stacking type inorganic compound with chemical composition shown as (MS)x(TS2)n. In addition, we took note of the alternately stacking compound that is produced by inserting a different atom in between the TS2 layers.      Incommensurate misfit layer compounds (MX)x(TX2)n (M; rare earth metal, Pb, Sn, Bi, T; Ti, V, Cr, Nb, Ta, and N=1,2) are now well known as low dimensional electronic systems in which the structure consists of alternate stacking of hexagonal transition metal dichalcogenides (TX2) layers and tetragonal metal monochalcogenide (MX) bi-layers. Fig.1 shows the stacking structure of this compound. As a structural characteristic, due to the lattice symmetries of these two kinds of layers being mutually different, MS layer and TS2 layer cannot have the same crystalline lattice any longer, resulting in the formation of mutually incommensurate lattices in one direction. When putting together a two-dimensional square lattice and a hexagonal lattice (regarded in this case as an orthohexagonal lattice), if the lattice constant in one direction is made uniform, the lattice constant in the other direction because a ratio of irrational numbers, that is 1:root3. Because of the incommensurate structure, the bonding between the layers is weak, making it possible to endow each layer with different functions to fabricate a nanoscale functionally graded material.      In this report, of the compounds with incommensurate stacking structures we used (MS)1.20 (TiS2)2 (M=La,Ce) and inserted a 3d transition metal between the TS2 layers, thus composing an interlayer compound. We studied the electronic state and magnetic properties thereof. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 249-256 金属セラミックス単結晶傾斜機能膜の作製とその電気・磁気的性質の解明 Preparation of a Metal/Ceramic Single Crystal Functionally Graded Film and Analysis of Its Electric and Magnetic Properties 田中信夫名古屋大学工学部 Nobuo TanakaNagoya UniversityFaculty of Engineering  In this study, functionally graded composite membranes were produced by the ultrahigh-vacuum simultaneous deposition method. These membranes consist of ceramic (MgO, CaF2, Al2O3) single crystal matrixes embedded with metal and semiconductor clusters whose gradient parameters such as volume ratio, crystal orientation, particle size and shape are modified. Then, we studied the macroscopic as well as local physical properties in which the gradient was reflected.      In this study, the following items are to be studied.      (1) Functionally graded metal-ceramics films are to be produced by simultaneously depositing metal and ceramics upon an alkali halaide substrate, which has been heated up, in the ultra-high vacuum.  Additionally, by creating a temperature gradient on the substrate, conditions are to be searched which would make intervals in the semiconductor cluster and metal, density, size, crystal structure and external forms in the composite membrane "the gradient parameters."     (2) The evaluation of the "gradient" of the produced sample is to be carried out by an optical microscope (absorption ratio, reflectivity measurement), a transmission electron microscopy (evaluation of particle size, distribution, crystal structure of the cluster) and a scanning tunneling microscope (measurement of particle size, distribution, local electric conductivity of the cluster).      (3) The local magnetic properties of a functionally graded transition metal-ceramics film is to be clarified in comparison with the structure analysis data of (2).     (4) Next, macroscopic conductometry is to be done by direct current 4 terminal methods. Then, the local electric resistance is to be measured using minute probes and STM, and it is to be compared with the two-dimensional distribution of the graded parameter obtained by the structural analysis method of (2).      (5) The effectiveness of making gradients in metal-ceramics composite membranes, nano granular dielectric films, and magnetic substance films as well as their applicability to the electron functional device are to be examined.      In fiscal 1996,  the basic research on (1) whether the gradient can be certainly adopted or not, (2) the possibility of making gradients in the "crystal structure change" and "magnetism" in addition to the concentration (vapor deposition quantity) and (3) the magnetism of a Fe-MgO graded composite membrane was conducted. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 257-266 レーザMBE法による強誘電体／強磁性体傾斜機能材料の創成 Formation of Ferroelectric/Ferromagnetic Functionally Graded Materials by Laser MBE and Their Physical Properties 田畑仁、金井真樹、川合知二大阪大学産業科学研究所 Hitoshi Tabata, Masaki Kanai and Tomoji KawaiOsaka UniversityInstitute of Scientific and Industrial Research  Research and development of functionally graded materials (FGMs) have been pursued with the goal of applying new thermal resistant materials to the field of aerospace technology, which is vital. Conventional FGM studies centered on structural materials, and in particular, much progress has been made in the area of graded ceramics/metal compounds with thermal resistance and oxidation resistance of ceramics and the high modulus of the metal structure. In structural materials, FGM studies have made headway, but in the field of functional materials, there are very few applications. Much remains to be researched for applications of FGMs in the electronic material field.     On the other hand, perovskite-type oxides have long been used for functional applications. They include dielectrics such as BaTiO3 (1)(2), ferromagnetics such as SrFeO3 and copper oxide superconductors (3) that were discovered by Bednortz et al. of IBM in 1986. These are important materials because of their wide variety of electric and magnetic properties. In recent years, the object of attention in particular are manganese oxides with pervoskite structure in which electric resistivity change over 10**5 (ohms) toward the external magnetic field. This phenomenon is called the giant magnetization effect (4)(5), and the physical properties of these oxides have great potential.     The purpose of this study is to form an artificial lattice with the graded structure of ferroelectric/ferromagnetics by laser ablation MBE. The aim is to clarify the effectiveness of the graded structure on the newly composed material's electric and magnetic properties. We also carried out material designing by computer analysis (molecular dynamics, orbital calculation, finite element calculation), in order to make possible predictions concerning crystal structures, electric and magnetic properties.      Ultimately, as the field of semiconductors progressed as a result of being able to control the band structure by combining joined materials (band engineering), through material designing with perovskite type oxides (perovskite engineering), we can open up new fields in the field of functionally graded materials. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 267-272 積層型金属窒化物複合材料の作製とメゾ界面評価 Preparation of Metal Nitride Multilayer Composite Material and Evaluation of Its Meso-Boundary 吉川信一　高橋昌男大阪大学産業科学研究所 S. Kikkawa, M.TakahashiOsaka Universitythe Institute of Scientific and Industrial Research  In order to achieve high functionality using various graded materials, the gathering and control of various information relating to heterogeneous phase interfaces is imperative. Magnetization is highly detection sensitive, and therefore it plays an important role is defining the properties of minor constituents on the interface, etc.       The possibility of giant magnetization stances, by stacking with non-magnetic substances or dispersing therefrom, it is important that the coercive force and magnetic resistance be increased.      Among iron nitrates, several types of compounds with varying contents of nitrogen are known. Fe16N2 has a bct lattice with a small amount of nitrogen configured in an orderly manner on (alpha)-Fe bcc lattice. (gamma)'-Fe4N is a ferromagnetic ((sigma)=190emu/g)in which the Fe atom has removed the fcc lattice and nitrogen is configured in the center. In (epsilon)-Fe x N(3>x>2), the Fe atom has removed the hcp lattice, and in the 4-coordinate position in between the lattices, the nitrogen atoms exist. Either iron nitrate are thermally unstable, and when they are heated to over several hundred deg.C, they release nitrogen and decompose. Thus, with a conventional metallurgical method, it is not possible to create compounds with higher nitrogen content.     However, using the high frequency sputtering method, by activating the nitrogen by means of plasma, we have been able to obtain iron nitrates with nitrogen contents close to FeN. The present theory is that large magnetization if the iron nitrate is caused when a small amount of nitrogen enters into the (alpha)-Fe lattice and wides the distance between the Fe-Fe atoms by a small margin.  The vital issue is how to provide stability to (alpha)-Fe with a small amount of nitrogen, in order to obtain a iron nitrate magnetic substance with the largest possible magnetism.      In this study, through the high frequency sputtering method, we fabricated a stacked thin film that has been configured with the metal Fe and AlN ceramics which has high covalent bond, stable even in extremely high temperature with low reactivity in the nano to meso order. We studied the magnetic properties thereof, and by utilizing the data regarding the metal nitride that has been acquired by our research group, we will report on the evaluation results for the stacking interface using spectroscopy. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 273-280 フェロおよびフェリ分子磁性体の混合による傾斜的磁性制御 Control of Graded Magnetic Properties by Mixing Ferromagnetic and Ferrimagnetic Compounds 大越慎一（財）神奈川科学技術アカデミー Shin-ichi OhkoshiKanagawa Academy of Science and Technology  Thus far, magnets were composed of such inorganic materials as metals and metal oxides. However, in recent years, research into ferromagnetic molecules which is based on organic radicals and metal complexes have been carried out. Ferromagnetic molecules enable the design of spin sources and ligands to be made with consideration to the interaction between the spins. Therefore, it is anticipated that various magnetic properties nonexistent thus far can be engineered. Among these, the Prussian blue analogs, show the highest magnetic phase transitional temperature (Tc) of all the stable ferromagnetic molecules. In addition, two types of metals which alternately cross-links the cyano groups make up a 3-dimensional structure (Fig. 1). Depending on the choice of metal, it can become ferromagnetic or ferrimagnetic.     Using these Prussian analogs, the following studies were carried out. (1) First of all, we used a Prussian blue analog as a model to examine the graded magnetic properties. A 3-dimensional complex was composed according to a new ferro-ferri mixed magnet concept in which ferromagnetic interactions where the electronic spins between the metals are parallel (J>O), and the anti-ferromagnetic interactions where the aforementioned are not parallel (J<O). (2) Next, by applying the ferro-ferri mixed magnetic concept, we attempted to invert the poles of the magnets using light (photo-induced magnetic pole inversion). (3) By electrochemically composing thin films of gradient composition, we studied their structures and magnetic properties. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 281-286 低次元発光材料の傾斜機能の研究 Study on the Graded Functions of Low-Dimensional Phosphor 遠藤忠東北大学大学院工学研究科 Tadashi EndoGraduate School of Engineering, Tohoku University  From past studies, ZnGa2O4 with spinel type structure has been the object of great interest as blue-emitting phosphor that is exhibited through ultraviolet rays and electron beam irradiation without activating impurities at the luminescent center. It is also highly regarded for its varied uses such as low-speed electron beam fluorescent character display tube made possible by its thermal stability. In this study, in order to achieve higher and increasingly varied functions, we looked into the possibility of "polychroming" of emission based on the grading theory.     Regarding the design of donor and acceptor in relation to the graded chemical composition and structure (lattice decay), or the control of the energy gap resulting from the substitution to the 4-coordinate site or the 6-coordinate site, we examined the results of the powdered sample obtained from the solid phase reaction and the single crystal sample obtained using the flux. Specifically, we studied the possibility of replacing the spinel structure Zn site (4-coordinate site) to Mn2+ or Cd2+, and the Ga site (6-cordinate site) to Al3+ or Cr3+, as well as the details of emission mechanism of self-activated luminescence. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 287-292 キャリア濃度傾斜熱電半導体単結晶の熱電特性に関する研究 Studies on thermoelectric properties for thermoelectric semiconducting single crystals with FGM structure of carrier concentration 海部宏昌東京都立大学工学部電子情報工学科 H. T. KaibeGraduate School ofEngineering, Graduate Course of Electrical Engineering, Tokyo Metropolitan University  A modification of the PbTe-based thermoelectric material to FGM can be effective for performance improvement and has a possibility of substantially magnifying the importance of future thermoelectric material. However, the diffusion junction seems to be necessary for junction of electrodes and materials with different carrier concentration and the temperature of the device is required to be raised to around 1100K that time. We examined the change of r before and after the temperature rise to 800K at Ar atmosphere gas pressure 1~3x105Pa in the stainless steel container in respect of n-type PbTe ingot material with carrier concentration of 1x1025m**-3. As the result, (rho) decreased after the temperature rise, and it was clarified that the decrease rate rises with the increase of the Ar pressure.       From the above result, it is clear that the thermoelectric properties of n- and p-type PbTe change by continuous use around 850K and the establishment of the control method and the clarification of the mechanism are important problems. Based on this, in this study, the temperature dependency of (rho) under the rising and falling temperature cycle in the Ar gas atmosphere was examined with regard to n-type PbTe ingot material and a sintered compact, and the identification of the sample was carried out by X-ray diffraction before and after the temperature rise. Moreover, changes in the thermoelectric properties in heat-treating were examined after it is vacuumized in a silica tube by way of controlling the change of properties with time, and the effectiveness of this method was scrutinized.       The measuring of thermal conductivity is the most difficult of the thermoelectricity parameters, and especially, in the case of PbTe-based chemical compounds, the thermoelectric properties change with the temperature rise to around 600K, the operating temperature range as seen above, and the change with time seems to accelerate during the measurement. Therefore, the thermal conductivity was measured in the temperature range under the room temperature in which measurement of high-precision and high-reproducibility is possible, and the analysis of the electron transport and the heat conduction mechanism were carried out along with the result of Hall coefficient, thermoelectric power and specific resistance. Based on this, the thermal conductivity in the operating temperature range was theoretically deduced, and its performance in the operating temperature range as a n-type thermoelectric converter was estimated. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 293-302 傾斜成長法によるCuInSe2系太陽電池の高効率化 Efficiency Improvement of CuInSe2-Based Solar Cells by Graded Growth Method 伊藤太一郎、芦田淳、＊伊崎昌伸、小見崇大阪府立大学工学部、＊大阪市立工業研究所 A. Ashida, ＊M. Izaki, T. Komi and T. ItoOsaka Prefecture University＊Osaka Municipal Tech. Research Institute  Various types of functional grading which would contribute to improving the efficiency of the next generation thin film solar cells were examined, and the basic studies and trial manufactures with the aim of grading CuInSe2-based thin film solar cells on the following 2 points were attempted.       From the viewpoint of the "fabrication of off-stoichiometry FGM" for the purpose of realizing the higher orientation and the larger grain size for a polycrystal CuInSe2 thin film, a basic experiment by two-source evaporation as well as the equipment design and preliminary experiment for three-source evaporation method were carried out. As for the two source vapor deposition which uses Cu2Se and In2Se3 as evaporation raw material, the lamination vapor deposition of two kinds of material, the simplest form of grading, by a quasi-flash evaporation method. A large difference resulted in the orientation of the obtained CuInSe2 thin film depending on the order of evaporation, and in case where Cu2Se was deposited first, a high orientation CuInSe2 thin film utilizing the natural orientation of Cu2Se in the first phase was successfully produced. In order to realize this process more precisely and at lower temperature and with introduction of the three-source evaporation method in mind, the evaporation means and equipment for each raw material element were examined.       The technique for electrochemically producing an functionally graded ZnO-based functionally graded thin film (ZnO film) from aqueous solution was examined so as to produce functionally graded ZnO layer, which can be applied to a low-resistant transparent conductive layer, namely, a window material, from high resistant n-type semiconductor layer consisting solar cells. In addition, the manufacture technique of a ZnO imitation onto a non-conductive substrate was examined. The resistivity, carrier concentration and mobility of a ZnO film are dependent on the produced cathodic potential, and a high-resistant ZnO film was obtained in the negative potential whereas, in the positive potential, a low-resistant ZnO film was obtained. By changing the cathodic potential during the process of electrolytic, a ZnO layer with excellent optical transparency and graded electrical properties was produced. Moreover, from the aqueous solution consisting of zinc nitrate and boron chemical compound, a ZnO film with excellent optical transparency and of the Wurtzite structure was chemically produced on non-conducting glass substrates without external power source. In addition, this ZnO film was electrochemically grown by electrolyzing in zinc nitrate aqueous solution in the negative electrode. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 303-307 光学的傾斜機能ポリマーの分子設計と機能発現の解析 Design and Characterization of Functionally Graded Photonics Polymer Materials 小池康博　二瓶栄輔　谷尾宣久　石榑崇明慶応義塾大学理工学部物理情報工学科・神奈川科学技術アカデミー Yasuhiro Koike, Eisuke Nihei, Nobuhisa Tanio and Takaaki IshigureFaculty of Science and Technology, Keio University/ Kanagawa Academy of Science and Technology  The problems of future communication enterprises are the improvement of a high-speed information network as a society infrastructure, the development of equipment for information terminals, and the development of application software, etc. Among other things, it is urgent to improve the network which enables the high-speed information communication.       The existing infrastructure network has been the telephone network. In view of the transmission capacity of this method, it is difficult to exchange smoothly moving image information with computers, even in the case of using single compression technologies. This is because in case high-speed electric signal is transmitted using the metal cable, the transmission loss increases due to the proximity effect, and therefore, long distance transmission is not possible.       The Ministry of Posts and Telecommunications has built the optical fiber network to realize the high-speed information communication society. More than 70% of the existing metal-cable-based information mainline system has been replaced with single-mode (SM) type optical fibers which have large transmission capacity, and the technologies which will fulfill the main role in the value-added networks such as ATM (Asynchronous Transmission Mode) have already started to be put into practical use. At present, 156Mbps or 622Mbps are set as a goal for the transmission capacity of network.       Currently, the biggest problem in constructing the value-added network is that what type of communication medium can be used for the access system which connects the information mainline system and individual houses or offices. High costs are expected since a great number of connections and divergences are required in this region, and it is costly to connect and branch off the SM type optical fiber of which the core diameter measures 5-10 micron. At this point of the end of fiscal 1992, the rate of the subscriber loop fiber optics is 2.9% of the total cable length, and the urgent development of this type of infrastructure is required now. In such a situation, low-cost plastic optical fibers which we have developed can be very much expected to be used for constructing the multi-media network with a high speed transmission system. In this paper, the result related to little-loss GI type POF developed recently is described center. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 309-316 複合因子傾斜化による熱電半導体焼結素子の熱電性能温度依存性制御 Controlling Temperature Dependency of Thermoelectric Performance of Sintered Thermoelectric Semiconductor by Means of Graded Composit Elements 梶川武信湘南工科大学 Takenobu KajikawaShonan Institute of Technology  The function of thermoelectric conversion material is mutual conversion between thermal energy (thermal power) and electric energy (electricity) which is represented by temperature gradient and heat flow. This is otherwise known as the Seebeck Effect and the Peltier Effect.      Macro factors which represent the properties of thermoelectric semiconductors in energy conversion are: Seebeck coefficient (alpha) (V/K), electric conductivity (sigma) (S/m) and(tau)thermal conductivity (kappa) (W/mK), and Z which is defined as the performance index Z=(alpha)2(sigma)/(kappa)(K-1) is closely connected the maximum conversion efficiency.      The figure of merit which is closely related to the efficiency is solely dependent on the material properties. In addition, Z has high thermal dependence.      The purpose in thermoelectric conversion is to obtain high system efficiency. Therefore, the ideal device function is one that can maintain high performance over a wide temperature range.      In this paper, by introducing the grading concept to thermoelectric material, we will seek to achieve a functional body through artificially grading thermal properties.      In this study, we will take up MgSi thermoelectric semiconductor, which has the potential for high performance due to the fact that it is safe, of low cost and has a complex structure known as the chimney-ladder structure.     The purpose of this study is to utilize the complexity of sintered bodies in contrast to the single crystal. By grading the structural factors in various levels which includes utilizing the controllable factors, we will endeavor to establish the technology for creating functionally graded thermoelectric devices which has high performance over a wide temperature range. To achieve this goal, first of all we will independently examine the temperature dependence of various factors which determine the performance. Specifically, we will report on the possibility of controlling the temperature properties of a sintered device with the composite introduction of the carrier concentration and macro structural change through the experimental results of sintered MgSi as an example. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 317-322 電解析出法によるビスマス－テルル系傾斜機能材料の合成 Synthesis of Bi-Te System Functionally Graded Materials by Electrodeposition Method 宮崎譲東北大学工学部 Yuzuru MiyazakiTohoku UniversityFaculty of Engineering  A material which has graded carrier concentration is expected to be developed in order to expand the practical temperature range of the Bi2Te3 system thermoelectric material as well as to realize high-efficient thermoelectric conversion elements.       The electrolytic deposition (electrodeposition) method is capable of obtaining metallic phases at around room temperature. It is also a synthetic method capable of controlling the composition and the particle size of electrodeposition films. In addition, since it requires simple equipment and it can be used for manufacturing optionally shaped samples, this method has been applied increasingly to the synthesis of II-VI group compound semiconductor films.       As for the Bi2Te3 film synthesis, a report on it has been made by Takahashi et al. recently as the relation between the metal ion concentration and the generation film as well as the effect of Bi ion concentration upon the conductivity were examined. More recently, a case of the electrodeposition of a (Bi, Sb)2Te3 film of which Bi is partly replaced by Sb was reported by Watanabe et al. This verified that an excessive addition of Sb ions promotes the dissolution of Sb. However, from the standpoint of the fabrication of functional gradient materials, it is much easier to control the composition by changing the deposition potential than to continuously change the solution composition during the synthesis, and it is advantageous even in terms of reproducibility and reliability. Moreover, it is known that, in the electrodeposition of intermetallic compounds such as II-VI group semiconductors, the composition of a deposition film can be changed more extensively by changing the potential than the metal ion concentration.       In this study, the objective was set as obtaining the basic data for producing the functionally graded Bi2Te3 system films in which carrier concentration (composition) continuously changes by changing the deposition potential using the electrodeposition method. Then, it was tried that the potential range that a Bi2Te3 film is got was clarified by making first, current-potential curve in Bi and in nitric acid aqueous solution including the Te ion. The Seebeck coefficient of a film was measured, in the range of the deposition potential, while it continues, and while the relationship between crystalline orientation, lattice constant, composition of a film got with the potential is examined. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 323-328 希薄磁性半導体傾斜構造の開発と巨大磁気光学機能性の研究 Development of Diluted Magnetic Semiconductor Graded Structures and Research on Giant Magneto-Optic Functionality 岡泰夫　梁田興平　高橋昌明東北大学科学計測研究所 Yasuo Oka, K. Yanata and Masaaki TakahashiTohoku UniversityResearch Institute for Scientific Measurements  A diluted magnetic semiconductor is a compound semiconductor which contains magnetic metal ions such as Mn, Fe, and Co as a part of positive ions. These materials show quite distinct magneto-optic properties in comparison with ordinary semiconductors due to the effect of magnetic ions in these materials. We have advanced the study of the optical property of this diluted magnetic semiconductor . The electrons which are given the quantum confinement effect can be categorized into the electron system which has interaction with magnetic ions as a result of "the diluted magnetic semiconductor quantum nanostructures" such as quantum well, quantum wire, and quantum dot being produced from the above-mentioned diluted magnetic semiconductors. Due to the electronic localization by the composition fluctuation of the magnetic ions, this diluted magnetic semiconductor nanostructure system also shows various physical properties which allow for more possibilities of application.       Based on the research we have conducted so far, we consider that there is a big future possibility in "fabricating functionally graded diluted magnetic semiconductor materials which have a gradient distribution of the magnetic ions on a nanometer scale and working on the development and application of these new magneto-optical properties." The purpose of this study is to produce a diluted magnetic semiconductor / graded magnetic structure quantum well which has continuous or graded change in the magnetic ion distribution, to control the magnetic interaction among the electronic quantum confinement effect and the electrons and the magnetic ions in this system by the graded quantum structure, and then to explore new magneto-optical properties and functional magnetism photoelectric conversion properties.      Therefore,      1) A quantum well structure and quantum dot which have the magnetic gradient of dilute magnetic semiconductor are to be developed.      2) The exciton condition and magnetopolaron condition as well as the dynamics in the diluted magnetic semiconductor graded quantum well structure is to be examined by the laser spectroscopy, and the features of the magneto-optical properties in the electronic state in which a graded exchange of interaction occurs is also to be examined.      3) It is necessary to examine the electron tunneling process and the gradient in the super magneto-optic effects using the time-resolved spectroscopy and to study the applicability to the magneto-optic devices. In this report, the results obtained and the future tasks are discussed. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 329-336 化学組成変調によるシリコン系薄膜のキャリア輸送特性の制御 Control of Carrier Transport Properties of Silicon-based Thin Film By Chemical Composition Changes 白井肇埼玉大学工学部 Hajime ShiraiSaitama UniversityFaculty of Engineering  In this study, the following was carried out for the purpose of applying the silicon system thin-films to solar cells: the development of a low-temperature film formation technology of, and the improvement of efficiency by grading the phase and composition of, and the evaluation of the carrier transport property of the high hydrogenation amorphous and crystal silicon (a-Si:H, (mu)c-Si:H) as well as its alloyed thin-films. (Si1-xGex, Si1-xCx) Specifically, (1) The research on the manufacture and the carrier transport property evaluation of graded semiconductor thin-films in which the chemical composition of Ge continuously and locally changes in the film thickness direction of the a-Si:H thin film. (2) By continuously changing the SiH4 dosage in the steady-state plasma of dichlorosilane (SiH2Cl2)/H2, a graded structure which has a continuous phase change from the amorphous to the crystallite in the film thickness direction is to be designed, and the result of the 2 items of the research aiming at the improvement in the optical absorption properties in the long wavelength region is to be reported. As grading is applied to the vapor phase thin film growth by the plasma CVD method, the following would be required. First of all, the basis thin-film material should be of high quality, namely, excellent in the photoconductivity. Secondly, there should be no fluctuation of the plasma by the introduction of guest gas (GeF4,SiH4). For this reason, the destruction efficiency of the guest molecules by the plasma needs to be much higher than that of the host molecule (SiH4,SiH2Cl2). Thirdly, along with the grading of these materials, there should be no formation of new defect levels which interfere with the light injection carrier transport. In addition, the manufacturing technology development of low-temperature silicon system thin-film, which meets these demands, is required. The result of grading from a-Si1-xGex:H (x=0-0.5) as well as a-Si:H(Cl) to the (mu)c-Si:H(Cl) phase as chemical composition modulation in the silicon thin film formation by the plasma CVD method is shown below. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 337-342 光学的線形・非線形傾斜機能型ガラスセラミックスの創製と評価 Fabrication and Evaluation of Optically Liner/Nonlinear Functionally Graded Glass Ceramics 小松高行　紅野安彦　坂井亮介長岡技術科学大学工学部 T. Komatsu, Y Benino  and R. SakaiNagaoka University of Technology  Functions and energy conversion by graded structure formation is an important pillar which will support the design and development of future functionally advanced materials. The development of new optical functionally graded material which is capable of utilizing light maximally and enabling the control of the light, as well as photoelectric functionally graded material which can efficiently convert light energy into electric energy will be more and more important in the future.       Recently, we have discovered optically nonlinear, transparent tellurite system glass ceramics which shows SHG, and it was found that the expression of the nonlinearity greatly depends on the type of the alkali metal ion of the mother glass. That is to say, the fabrication of linear / nonlinear, transparent and functionally graded glass ceramics, (or graded type combination functional material of glass and ceramics) which has never been conceived until now, will be possible by grading the distribution of alkali metal ions and other composition ions.  The material which has graded nonlinearity is capable of the conversion of the light energy (SHG) and the containment of light, and the graded structure itself can be considered to be a device. Moreover, in the glass or glass ceramics method, the manufacturing of long length fiber and wave guide is comparatively easy, and those method have many advantages as material fabrication processes.       Among other oxide glasses, the tellurite system glass exhibits unique characteristics such as low-melting-point, high refractive index, high dielectricity, excellent IR transparency and so on, and, especially, research of the nonlinear optical properties has been actively carried out recently. However, for the first time ever, the manufacturing of transparent tellurite system glass ceramics by crystallization in an effort to search and develop a material which shows new optical functions is being attempted by us. This study aims at further developing the transparent tellurite system glass ceramics showing SHG which we discovered so as to manufacture optical nonlinearity distribution type functionally graded material which completely differs from the conventional flexibility distributed functionally graded material. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 343-348 非晶質傾斜超格子を用いた極低雑音アバランシェ増幅型光導電膜の研究 Avalanche Multiplication Photodiode Films using Functionally Graded Amorphous Super Lattice Structure 安藤隆男　澤田和明　中西洋一郎静岡大学電子工学研究所 Takao Ando, Kazuaki Sawada  and Youichirou NakanishiShizuoka UniversityResearch Institute of Electronics  The development of solid-state imaging sensors has been remarkably promoted in the recent years and they are now used as not only home video cameras but also cameras for the high-definition television broadcasting. On the other hand, the research for further sensitization and pixel multiplication of the imaging sensors is indispensable in preparation for the future multi-media society. These demands for further sensitization and pixel multiplication are contradictory to each other since the reduction of the photosensitive area of a pixel naturally results from the reduction the pixel area as the picture element number increases. This causes the signal current to decrease, and the S/N ratio lowers. The average photoelectric conversion efficiency of the current solid-state image sensors is almost 1. Therefore, in order to realize the ultimate element capable of picturizing images with minimum quantity of light which even the human retina cannot perceive, the effective quantum efficiency must be improved by equipping the photoelectric conversion system of each pixel with a low-noise amplification mechanism. In the field of imaging sensors, avalanche multiplication has been regarded as an ideal form of an amplification mechanism which can increase the signal charge directly without enlarging the pixel area. Based on this idea, it was considered that the above problem could be solved by applying the avalanche multiplication to photoexcitation electrons without increasing the noise so as to raise the nominal quantum efficiency over 1.       Given the foregoing, we took notice of a-Si:H photoconductive film which has low dark currents and spectral sensitivity distribution similar to that of the human eye and started the research of the layered-type solid-state image sensing sensor using this material. Until now, we have got ahead of the world with a successful application of the avalanche multiplication to the photocurrent of the amorphous silicon pin photodiodes ahead of the world. The main factor for this success can be credited to the improvement of the mobility by the residual stress relaxation of the membrane and the reduction of the dark currents by the improvement of the membrane quality. On that occasion, the photocurrent measured about double with operating voltage at 45V. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 349-354 多孔質傾斜機能熱電材料の製作と最適化 Synthesis and optimization of functionally graded porous thermoelectric materials 大中逸雄、安田秀幸大阪大学工学部 Itsuo OHNAKA and Hideyuki YASUDAOsaka University  The thermoelectric material converts electric energy into thermal energy or thermal energy into electric energy.      The existing thermoelectric conversion system has used bulk thermoelectric materials. Recently, however, power generation and heating / cooling systems using porosity have been proposed by Echigo et al. The combustible gas which flows in from the lower end passes through the porosity area and then burns in the upper end, and the upper part of the terminal is heated up by the exothermic reaction. Since the gas which passes through the pores cools them down and transport the heat to the higher temperature side, it can create a large temperature difference between the two end of the device without help of a cooling system.       As for the ordinary bulk material, materials development, organization control have been pursued with the aim of attaining a higher figure of merit Z which satisfies the condition in which the electric power which the element can obtain is balanced with the heat and energy conversion efficiency.      In the case of the porous thermoelectric material, the temperature distribution in the element is decided by not only the heat conduction of the pores but also the heat transportation to the higher temperature end as well as the cooling by the gas which passes through the porous area.           The research and evaluation should be conducted on not only the material and organization control to realize the maximum figure of merit Z but also the organization the material study which corresponds to the porosity thermoelectric system. However, at present, the research on the porous thermoelectric material from the material standpoint is being conducted on a limited scale.      In this study, the focal point is the development of porous thermoelectric materials and the performance improvement of the element which satisfies the demands related to thermoelectric properties (physical characteristics) and heat-resistance (chemical characteristics) by means of graded functionalization. However, since the manufacturing process of porous thermoelectric material and the evaluation method of its thermoelectric properties have not been established yet, the following research is now being carried out with regard to the functionally graded porous thermoelectric material this fiscal year.      1. The establishment of the porous formation process      2. The trial manufacture of functionally graded porous thermoelectric device (P-type)      3. The examination of characteristic measuring methods of functionally graded porous thermoelectric device      In the formation process of No.1, the porous formation by hot pressing methods including the SPS sintering were attempted with expectation of short time porous formation of the solid-liquid coexistence state particles by laser irradiation. As for the functionally graded thermoelectric device, a trail manufacture was carried out using (Bi, Sb) 2Te3 for the high-temperature, FeSi2 for the mid-temperature, and PbTe for the low-temperature part. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 355-360 光増感反応による高分子の光電気的機能の傾斜化 Fabrication of an Optoelectrical Functionally Graded Polymer Film Using Photosensitized Reactions 山下和男　播磨裕広島大学総合科学部 Kazuo Yanmshita, Yutaka HarimaHiroshima UniversityFaculty of Integrated Arts and Sciences  Around 1980, it was reported that a certain kind of conductive polymers could be useful as battery and material for diodes.      The development of the new methods which enable p-n gradient and de-p- or de-n-gradient will be one of useful approaches for developing and improving the efficiency of organic electron devices produced with conductive polymers.       Tris (2,2'-bipyridine) ruthenium (II) ([Ru(bpy)3]2+) functions as a desirable photosensitizer which has a distinct light absorption peak at around 450nm of the visible band. In a system in which methyl viologen, etc. coexist, the excitation species ([Ru(bpy)3]2+*) of the above complexin produce [Ru(bpy)3]3+ with strong oxidizability as a result of oxidazation quenching. In the meantime, in case where EDTA, etc. exist, the reduction quenching reaction is generated and [Ru(bpy)3]+ with big reducing power is formed. Therefore, it seems possible to selectively oxidize or reduce part of the polymer thin-films utilizing oxidization or reducing power of [Ru(bpy)3]+ or [Ru(bpy)3]3+ which are formed by photosensitize reactions triggered by optical illumination upon the semiconductor polymer interface which has contacted solution including [Ru(bpy)3]2+ and reduction quencher or oxidation quencher. That is to say, it is possible to obtain a p-n gradient or de-p (n)- gradient.       From the above viewpoint, first of all, the anionic (p-) and cationic (n-) doping as well as de-doping of the semiconductor polymers utilizing the reductive reaction and the light intensifying oxidation of [Ru(bpy)3]2+ were examined, and these reaction mechanisms were clarified in this study. Next, the methods for potential grading which utilize the merit of the electrochemical technique and the light doping method as well as the development of the potential regulation light doping method were carried out. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 361-365 プラズマ粉体処理によるミクロ傾斜機能構造を有する熱電材料セラミックスの開発 Development of thermoelectric ceramic materials with functionally graded microstructures prepared by plasma powder treatment 小柳剛、岸本堅剛、＊松原覚衛山口大学工学部　＊山口東京理科大学 T. Koyanagi, K. Kishimoto and K. Matsubara*Faculty of Engineering, Yamaguchi University* Science University of Tokyo in Yamaguchi  It is known that the figure of merit Z=S2(sigma)/(kappa) (S: Seebeck coefficient, (sigma): conductivity, (kappa): thermal conductivity) of the thermoelectric conversion material gets larger, as the material parameter A=m*3/2(mu)/(kappa)ph gets bigger. In this equation, m*, (mu) and (kappa)ph stand respectively for the effective mass, mobility and lattice thermal conductivity of the carrier. To improve of the figure of merit of the thermoelectric conversion material, the method for enhancing the material parameter A of the existing materials by the structure control is being considered in addition to the one for developing new materials with large parameter A. Up until now, we have carried out the research for increasing the figure of merit Z by improving (mu)/(kappa) while controlling the fine structures of the grain boundaries and interfaces of sintered compacts of thermoelectric conversion material using the plasma powder processing technology. This technology enables to treat the surface of the raw material powder of the sintered compact and sinter it and then to form graded layers of minute structures, elements and compositions in the grain boundaries and interfaces.       In this study, the aim is to establish the fine structure control technology of thermoelectric conversion material sintered compacts by the plasma powder processing as well as to improve the performance of the thermoelectric conversion material by giving micro functionality to the grain boundary of sintered compacts from the standpoint of the semiconductor engineering. In addition, by applying the plasma powder processing technology, functionally graded junction of different thermoelectric materials will be attempted, which controls not only thermal stress relaxation but also the electronic structures of the grain boundaries.       This fiscal year, a sintered compact made of SiGe powder which has been treated by diborane (B2H6) plasma was produced by the discharge plasma sintering process and its thermoelectric properties were examined for the purpose of controlling the potential barrier in the grain boundary and interface by doping impurity (B) to the grain boundary of thermoelectric conversion material sintered compacts. Moreover, by treating SiGe powder doped with B in the silane (SiH4) plasma, a Si-rich layer with larger bandgap than SiGe was produced in the grain boundary of the SiGe sintered compact, and the thermoelectricity performance improvement by the energy filtering effect was studied as well. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 367-372 傾斜機能材料の化学的生化学的性質「生物を模倣した高分子傾斜材料の設計」 Chemical and Biochemical Properties of Functionally Graded Materials: " Biomimetic Design of Polymer " 小野勝道茨城大学工学部 Katsumichi OnoIbaraki University  The main component of the biological tissue is the biopolymer chemical compounds such as cellulose in the plant tissue and protein in the animal tissue. The macroscopic graded structures of the biological tissue have been obtained as a result of the controlled chemical reactions over the long term, and from the viewpoint of materials science, it is a very interesting subject to fabricate artificial material in imitation of the process of forming graded structures and graded organizations. However, the problem is how to shorten the time needed for the histogenesis.       In the biotissues, soft organizations such as the skin and the ligament form graded structures of the component and organization, and the elastic modulus gradient has been achieved. Since polymer materials have relatively low melting points, it is supposed that graded structures can be easily formed by using the simple diffusion of the components in the melting state. In fact, however, achieving graded structures by this method is almost impossible. In a general formation processing condition, a formation cycle is within a few minutes whereas the diffusion length of polymers is of the micron order, so it is a far cry from the formation of the graded organization. Therefore, it is necessary to consider other methods to achieve macro graded organization in polymers.       In this study, two methods are proposed in order to achieve the graded organization. The first method is to form the graded organization using small molecules, which react with the polymers without using the diffusion of the polymers. The small molecular diffusion coefficient is sufficiently high in the melt of polymers of large molecular weight, and it is suitable for the formation of the graded organization. In this study, we aimed at the achievement of graded elastic modulus of the mm order by the diffusion control bridging of the cross-linking agent in the elastomer. The second method uses photosensitization polymerization. As photopolymerization is conducted by dissolving polymers in the different monomers with the help of the cross-linking agent, a gradient corresponding to the rate of polymerization is formed in the thickness direction of the polymeric film since the light dims due to the light absorption inside the film. Therefore, a graded composition in the thickness direction of the film can be achieved. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 373-378 人工生体構成材料の作製と応用一傾斜機能型人工歯根の試作一 Manufacture and Application of Artificial Organism Composition Materials-Trial Manufacture of Functionally Graded Artificial Dental Roots 亘理文夫、佐相史徳＊、横山敦郎＊、宇尾基弘、川崎貴生＊北海道大学歯学部歯科理工学講座、＊歯科補綴字第一講座 Fumio WATARI, Fuminori SASO*, Atsuro YOKOYAMA* , Motohiro UO and Takao KAWASAKI *Hokkaido UniversitySchool of Dentistry*Department of Removable Prosthodontics, School of Dentistry  The natural materials of plants and animals form structures in which micro and macroscopic organizations and components are functionally graded so as to meet the various demands required of their materials such as strength, ductility, and weather-resistance. Therefore, essentially, the functionally graded structures can be regarded as ideal forms for the biomaterials.       In this study, the concept of functionally graded material was applied to prosthetic implants (artificial dental roots). A prosthetic implant is conducted, in case of the loss of dentition due to injuries, aging, etc., for the purpose of recovering occlusal and masticatory functions and it is implanted in jaw bones (substructure) and mounted with prosthetic appliances (superstructure) such as dentures, etc. The part of the substructure buried in jaw bones is formed in the shape of screw, cylinder, or blade, and the part exposed above jaw bones is formed into a bridge abutment shape so that the superstructure such as dentures would well fit.       Functionally graded implant samples have been produced by combining materials that have excellent affinity. The upper part of such samples are made of titanium metal with excellent strength characteristics since the repeated stress loads are directly imposed there, and the buried lower part being made of apatite ceramics which is the main component of dentition.       In this study, a titanium/apatite (Ti/HAP) system functionally graded implant was molded at CIP pressure 400MPa and 900MPa and produced by sintering. To evaluate its biocompatibility, miniature test pieces (2(phi)x6-10mm) were manufactured and buried in rats and rabbits, and the possibilities of the inflammatory reaction and the degree of neonatal bone generation were examined and displayed by microscopy or EPMA (Electron Probe Microanalysis) or by the element mapping method using X-ray Scanning Analytical Microscope (XSAM).       The functionally graded sample was made cylindrical and one end was made of pure titanium. The concentration was graded in the length direction, and the other end was made of highly apatite-rich material such as Ti-20%HAP. In the following report, such samples shall be referred to as Ti/20HAP. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 379-387 植物の階層的傾斜構造 Hierarchically Graded Structures of Plants 天田重庚群馬大学 Sigeyasu AmadaGunma University  One of the features of the plant is that it is not composed of various organs as in the case of animals, rather its organs above the ground all share the basic structure called the cell. The cell has firm cell walls, and it cannot move to other places once it is formed since it has no motility. Therefore, the stacking system as in bricklaying was inevitably adopted in order for plants to grow. Moreover, in order to obtain energy necessary for sustaining life, conquering the battle of survival in search of light has been a prerequisite for them. Therefore, for the aboveground part which receives light, the plant adopted the system in which the part which always keeps division has been put in the tip of the shaft. In the meantime, it was forced to cope with the change of the environment tactfully since it cannot move from a place where it has the root.       Generally, the plant has a tendency to grow upward since the higher it grows the wider the space is that is available for it. However, the branches and the trunk need to support the leaves for the photosynthesis so the plant cannot grow unlimitedly beyond its supporting capacity. Therefore, the morphological structure of the plant is often determined by the balance between its phototropism for growing toward the source of light and geotropism for supporting itself. The phototropism is a biological demand whereas the geotropism is a physical or mechanical demand, and the structure of the plant can be rightly regarded as a product of compromise of both demands.       Such plant has kept the evolution by means of the superior heredity throughout ages, and the intelligence acquired over the period far exceeds our imagination. This study's aim is to clarify the intelligence which the plant acquired over the long term in light of the concept of functionally graded material. As research objects, bamboo with superior features and other plants were chosen, and the study was conducted along the following lines.      The plants as      -a graded structure     -a composite material      -a hierarchical structure      -a adaptive structure body Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 389-394 生体活性傾斜機能材料の設計 Design of Bioactive Functionally Graded Materials 小久保正　宮路史明　金鉉敏京都大学工学研究科 T. Kokubo, MIYAJI Fumiaki and H.-M. KimKyoto UniversityFaculty of Engineering  Generally, when an artificial material is implanted in a defective part of bones, the organism wraps it with a fibrous capsule and isolates it from the surrounding bones. However, some kinds of ceramics, albeit a few, do not cause the formation of capsula fibrosa, and rather they contact the bone directly and form a strong chemical bond. These are called bioglass, sintered hydroxyapatite, and A-W glass ceramics to mention a few. They are referred to as bioactive materials and they are already used as useful bone repair materials. However, due to its poor fracture toughness, these ceramics materials cannot be used as the alternative material for the bones constantly imposed of heavy loads such as thighbones and shanks. At present, the material used for these purposes is the one in which thin layers such as hydroxyapatite are formed on metallic material such as titanium metal by the plasma spraying method, etc. However, in this method, the hydroxyapatite powder is instantaneously heated up to above 10,000deg.C and the particle in a half melt state is sprayed to the metal substrate so it is difficult to control the structure and composition of the apatite layer and to combine this layer firmly with the substrate.       By forming a graded structure in which the alkali ion concentration gradually decreases from the surface to the inside on the titanium metal surface, a bioactive functionally graded material can be produced, which combines with the bone by means of an apatite layer similar to bioactive ceramics which can be formed in the organism. This study aims at clarifying the guideline for fabricating this type of bioactive functionally graded material by the method for treating titanium metal in alkali aqueous solution. This study aims at clarifying the guideline for fabricating this type of bioactive functionally graded material by the method for treating titanium metal in alkali aqueous solution. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 395-402 植物における傾斜機能特性の発現機構（細胞の外環境検知能力と自己組織化） Adaptive Growth Mechanisms of Design Architecture of FGMS in Plants  (Cell's Capability of Extracellular Environment Detection and Self-Organization) 野方文雄姫路工業大学工学部機械工学科 Fumio NogataHimeji Institute of TechnologyDepartment of Mechanical Engineering,Faculty of Engineering  Living creatures pay fullest attention to the surroundings to survive. Upon finding enemies, they defend themselves or escape. Upon coming across preys and food, they get them. The original perception, functionality, organization and structure, which have been cultivated while exercising ingenuity for about four hundred million years after the life advanced from water to land, truly fascinate us from any viewpoint and teach us a lot. Therefore, for the living things, forms and organizations have a great significance macroscopically as well as microscopically. From various standpoints, types of the defense method the living organism has adopted so that their bodies may not be crushed by the dynamics environment of the outside can be classified as follows.      (1) By changing the microstructure      (2) By changing the size and/or shape of a body     (3) By combining the type (1) and (2) (Fig.1)      Among these, in the category of type (1), there are many examples of the internal structures precisely and optimally graded as to their size and configuration. From old, research on the design concept of the organism has been carried out as "significance of the form in the organism." In order to acquire the substantial understanding, however, it is indispensable to systematically clarify the mechanism of the external environment perceptive ability on a cellular level, of the information processing from the outside, and then the construction (reconstruction) of the soft/hard tissues. The final goal of the research in this study is to systematically clarify the significance and expressed mechanism of the graded organization and structure which can be observed in the organism, while elucidating the perceptive ability of the cell for the external environment load. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 403-412 耐候性鋼安定さび層を担うクロム置換ゲーサイトの傾斜組成と大気腐食抑制機能 Graded Composition of Stable Rust Layer of Cr substituted Goethite Formed on Weathering Steel and Suppression Mechanism on Atmospheric Corrosion 三沢俊平室蘭工業大学工学部材料物性工学科 Toshihei MisawaDepartmennt of Materials Science and Engineering,　Muroran Institute of Technology  The weathering steel is known to be low alloy steel of which atmospheric corrosion resistance is improved by a protective rust layer formed in the steel surface. Mainly in 1970's, the structure of the protective rust layer was actively discussed based on the exposure test result conducted for a few years. As a result, until recently, the final structure of the protective rust layer which proves anticorrosive had been regarded as consisting of the amorphous rust layer of the internal layer in which Cr, Cu, and P are concentrated. In the meantime, based on the long term atmospheric corrosion test over a quarter of century, we have indicated recently that the amorphous rust layer is in the intermediate stage of the long term rust phase change and the (alpha)-FeOOH type goethite structure is the final structure of the protective rust layer, thus clarifying the long term process of the weathering steel rust layer. That is to say, the atmospheric rust phase goes through structural transformation from (gamma)-FeOOH (lepidocrocite)-> amorphous FeOOH -> (alpha)- FeOOH (goethite). The final protective rust layer after the long term exposure has been already reported to consist of (alpha)-(Fe1-x,Crx)OOH (Cr-substituted fine goethite) in which fine rust crystals are tightly condensed. It has been also confirmed domestically that goethite is the final protective phase based on the use of bare weathering steel for the oldest Japanese bridges and in U.S.A as well with regard to the atmospheric rust of the long term exposure test steel.       In this study, a comparison was made between artificial and natural rust using the weather-resistant final protective rust layer formed in the long term atmospheric corrosion test and Cr-substituted goethite artificially raised by applying the natural product. By so doing, the result of the examination on the structure and properties of the final protective rust layer which consists of the Cr-substituted goethite layer which we have discovered in advance will be reported in detail. The feature of this study is the evaluation of the effect of the Cr-substituted amount upon the anticorrosive function by examining the ion selectivity in the Cr-substituted fine goethite membrane from the viewpoint of the graded composite distribution in the rust layer of the Cr-substituted fine goethite which constitutes the final protective rust layer. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 413-418 水素電池長寿命化、高速活性化のための傾斜機能希土類系水素吸蔵合金に関する研究 Research on Functionally Graded Rare Earth Metal Hydride for Battery Life-Lengthening and High-speed Activation 岡田益男　中村元　高村仁東北大学工学部 Masuo Okada, Hajime Nakamura and Hitoshi TakamuraTohoku UniversityFaculty of Engineering  Looking back on the history of the development research of metal hydride as nickel hydrogen battery, it has been done less than the research from the standpoint of the material organization control. This is because the development research which was given higher priority was the one finding out how the pressure-composition isotherm with the hydrogen, which is an important battery characteristic, can be changed by additive elements, particularly on rare earth-Ni system alloys and Ti system alloys. Additionally, the requirements for the current metal hydride battery are as follows     (1) The reversible hydrogen storage and emission should be large.      (2) The corrosion resistance for alkaline solution should be excellent.      (3) They are expected to be stable even in case of repeated charge/discharge. At present, the problem is (3), the stability or the life duration. It has been indicated that the life of battery can be reduced by discharge and charge as these cause micronization and decomposition reactions of the alloy.       As a life-lengthening measure for the battery, it is reported that micro-encapsulation is effective, which conducts Co addition and wet electroless deposition of copper coat to the alloy powder in the rare earth -Ni(LaNi5) system alloy. Additionally, in the alkaline solution, segregation occurs on the surface of LaNi5 alloy powder by the oxygen, and it becomes La(OH)3, and nickel of deposited metal state seems to work as a catalyst of the hydrogenation reaction. In line with these results, this study aims at experimentally producing compound metal hydride powder which is ideal for the high-speed activation and life-lengthening of nickel hydrogen battery.  The ideal hydrogen alloy powder has graded hydrogen storage functions in it, the surface of which is excellent in corrosion resistance and catalysis and the inside consists of a phase capable of storing high capacity hydrogen.       In this study, the LaNi5 system alloy has been selected, which has been favorably studied with regard to practical application as the initial activation is easy, and functionally graded metal hydride will be produced experimentally. Specifically speaking, the goal is to produce alloy powder, the surface of which is excellent in corrosion resistance and catalysis and the inside consists of a LaNi5 phase. This fiscal year, optimum conditions for chemically etching the surface of alloy powder are to be examined. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 419-426 イネ科植物の茎の構造と組織形成における傾斜構造の発達過程の解析 Analysis of Growth Process of Graded Structures in Organizational and Structural Formation of Gramineous Plants 高橋清　後藤雄佐　中村貞二東北大学農学部 K. Takahashi, Y. Goto and T. NakamuraTohoku UniversityFaculty of Agriculture  There have been some research reports on natural functionally graded materials and as for the plant field, the report on the stem structure of bamboo by Amata et al.,(1996) is one such example.       Bamboo belong to the Gramineae along with rice plant, wheat, corn, sugar cane, and so forth.       According to the research by Amata et al., plants with the nodal structure such as bamboo (Gramineae) have a cross-sectional microscopic graded structure as well as a macroscopic graded structure of the internode intervals and these two graded structures functionally cooperate.      This study is intended to analyze the process in which these graded structures are formed based on the research by Amata et al.      To begin with, sweet sorghum (Sorghum Bicolor Moench) was chosen as a study material since, among the gramineous plants, this typical crop forms many internodes in a short period of time.      The gramineous plants have actual structural differences as the stem has a node (knot) as can be clearly recognized in bamboo. There are nodes in sweet sorghum as well, and the interval between nodes is called an internode. A long extended stem (culm) is composed of several or a dozen of internodes (elongation internode).  The first few (basilar) internodes elongate very little (they are called non-elongate internodes) whereas the elongation can be observed from the fifth or the seventh internode upward, and the higher the internode, the longer it grows. One internodes from the half position upward usually measure 20 to 30 cm. In this study, we took a fresh view of the graded structure which consists of a few elongate internodes of the stem, particularly the lower part of it, and we also analyzed its structure based on the accumulated measurement results as well as the survey results from cultivating the crop. Especially, this fiscal year, efforts were directed to acquiring a total grasp of the process in which this graded structure that is formed. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 427-434 電気化学的ポテンシャル勾配を持つルテニウム三核錯体のピラジン架橋オリゴマー Pyrazine-Bridged Oligomers of Triruthenium Cluster Complex with Electrochemical Potential Slope 伊藤翼東北大学大学院理学研究科 Tasuku ItoTohoku UniversityGraduate School of Science  It is known that the oxoacetato cross-link ruthenium trinuclear complex ([Ru3O(CH3COO)6(L)3]+) (Figure 1) exhibits 4-stage 1 electron oxidation-reduction wave which is electrochemically reversible in a solution. It is possible to form multimers such as a dimer and a trimer by using this complex as a unit and making linkage by means of cross-link ligands such as 4,4'-bipyridine and Pyrazine. Such multimers also show reversible and multi-staged oxidation-reduction behaviors, and are capable of reversibly transferring 4 electrons per unit, namely, 12 electrons for a trimer and 16 for a tetramer.       The research conducted until now has proven that this oxidation-reduction potential largely depends on pKa of the terminal ligand (L). This is due to the electron-donation of the terminal ligand, and corresponds to the fact with be difficult to oxidize, if it is difficult to reduce, if the electron density on the three-nucleon skeleton is high, and if it is low.       In such a background, we applied for Scientific Research on Priority Areas on the assumption that it would be possible to form an electrochemical potential gradient in line with the oligomer chain by appropriately selecting terminal ligands (L) in the above-mentioned multimers. The goals of this study are as follows:      1. To fabricate a chemical compound group of the above multimers with an electrochemical potential gradient and to examine the formation of the gradient electrochemically.      2. To study the relation between the degree of the gradient and the electron transfer behavior in line with the oligomer chain. The research for 1 was mainly carried out this fiscal year. As a chemical compound synthesis strategy for forming a gradient, we came up with 2 methods;      (a) configuration control of the terminal ligand and      (b) configuration control of the "Ru3" skeleton. Moreover, as a preliminary research for Goal 1, a trial experiment was launched which evaluated based on the spectroscopic technique the electronic transfer rate between the "Ru3" skeletons on the dimer (inter-skeleton mixed-valent dimer) of "Ru3" which has an electrochemical potential gradient. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 435-442 濃度傾斜表面による表面化学波の伝播プロセス制御 Propagation Process Control of Surface Chemical Wave by Graded Concentration Surface Potential Gradient 朝倉清高山口良隆　大西　洋東京大学理学部スペクトル化学研究センター東京大学大学院理学系研究科化学専攻 K.Asakura, Yoshitaka Yamaguchi and Hiroshi OnishiThe University of TokyoResearch Center for SpectrochemistryThe University of Tokyo  As for the surface of Pt(100) as well as Pt(110), it is known that the self-organized structures, in which the concentration of the absorbents has temporally regular changes, can be formed during CO oxidation reactions or NO+CO reactions. Additionally, these self-organized structures formed on the surface can be controlled as to their formation mode and propagation velocity by chemically modifying the surface. We have attempted the propagation control of the chemical wave which is the basic configuration factor of the self-organized structure by modifying the surface of Pt(100) and Pt(110) using various techniques. For example, we have succeeded in changing the spatial periodicity of the chemical wave by systematically arranging the fine dots on the surface of the titania, and also changing the generation condition of the chemical wave by depositing submonolayer gold. Moreover, we have found that the direction of the chemical wave can be controlled by means of total reflection and refraction. However, it is difficult to regulate the propagating direction of the chemical wave.       This study aimed at achieving the control of the propagating direction of the chemical wave during CO oxidation reactions on the platinum surface by establishing and utilizing the gold concentration gradient on the platinum surface. To accomplish this, the gold concentration gradient should be clarified. Since the PEEM method (photo emission electron microscopy) which has been used for observing chemical waves and self-organized structures of the surface is not capable of elemental analysis, it is difficult to measure the concentration gradient. For this reason, in addition to the PEEM method, using X-ray as a light source so as to furnish elemental analysis capacity, XPEEM (X-ray photo emission electron microscopy) equipment capable of detecting the concentration distribution was developed in this study. This equipment is capable of LEEM (Low energy electron microscopy) measurement to examine the spatial differences in the surface structures. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 443-452 生体組織傾斜構造に類似の細胞培養床の作成 Cell Culture Substrates consisting of Collagen Supramolecular Aggregates in a Graded Structure 林利彦東京大学大学院総合文化研究科 T. HayashiThe University of TokyoGraduate School of Arts & Sciences  In the living organism, there are gradients not only of the configuration of cells which have a large number of different functions but also of various materials or physical quantity.       The conditions of the cytodifferentiation such as cell proliferation, forms of the cell, gene expression, effect of the cell on the extracellular matrix construction are influenced by the extracellular matrix environment. Therefore, it is considered that the activity of the cell in the living organism is also influenced by the extracellular environment.       What kind of experiment and research programs are capable of investigating the biological functions of the graded structures in the configuration and extracellular matrix construction in which differentiated cell in the biotissue are graded?       We have examined the relation between the skeleton construction structure and the collagen protein of various tissues such as the skin tissue of animals.       These diversified organization structures have a fundamental topology that is universally applicable to all so we assumed that the peculiarity of the organizations could be explained by the differences in quantity and aggregation conditions.       What could be done to experimentally examine the biological functions which the graded ultrastructure of the extracellular matrix protein has? The individual cell differentiation induction or the maintenance of the differentiated condition is assumed to be influenced by the extracellular matrix ultrastructure, namely, the cellular environment. On the other hand, the interactions among different organizations are important for the differentiation of the cellular structures and the maintenance of it. The histodifferentiation is supposed to be induced or maintained by the interactions between the graded distribution of the differentiated cells and the graded construction of the extracellular matrix ultrastructures. However, it has been deemed impossible to actually construct the model as an experimental system and verify the speculation due to the limitation of the methodology.       It was in this context that we came across the concept of Scientific Research on Priority Areas, "functionally graded material" and we thought interesting consideration and experimental research would be possible by taking into consideration the relationship between this concept and the biotissue structure. On the assumption that the graded structure of the organism is related to biological significance or biofunction, verification of this by using the cultured cell was considered.       Taking part in the Scientific Research on Priority Areas, we thereby would like to advocate a hypothesis that "the graded structure has a function, and this function is related to the homeostasis maintenance of the organism structure and function." Then, we proceeded with collecting the necessary or lacking information in order to work on the verification of this hypothesis.  Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 453-458 銀－スズ合金の耐硫化性及び電気伝導性に対するスズの傾斜組成化効果 Effect of Sn Graded Composition on Antisulfidation and Conductivity of Ag-Sn Alloy 高井治　井上奏志名古屋大学工学部 Osamu Takai and Yasushi InoueNagoya UniversityFaculty of Engineering  Up to now, gold has been used as a material for contacts due to its excellent electrical conduction property and chemical stability. Silver, on the other hand, has better conductivity than gold and far cheaper, so it is expected to be a material for contacts in place of gold. However, since silver has a problem of antisulfidation, easily reacting with sulfur compounds in the atmosphere and producing hydrosulphide, it has a low reliability as a contact material.       We have been carried out a research on the alloying effect upon antisulfidation by producing silver base alloy thin-films from alloy targets of various metallic elements and silver using the sputtering technique. As a result, it has been proven that the antisulfidation can be improved by alloying In or Sn. These metallic elements are very much expected to be alloying elements for high sulfide-proof contact materials because of their past records of electronic component application (solder material), high-speed film formation, and their atomic numbers being close to that of silver. Given the foregoing, the alloying element content dependency on the antisulfidation was investigated on both elements and it was proven that sulphurization did not occur at a content rate over about 30at. % for both Sn and In. However, as the result of such high-density alloying, the electrical resistivity increased, thus creating a new problem of solderability deterioration. Therefore, this study aims at, first of all, producing a silver base alloy thin-film in which Sn is composed in a graded manner by the multidimension radio frequency sputter, and then establishing the composition modulation condition for optimizing its electrical characteristics and antisulfidation as a contact material. Additionally, the development objective for this alloy as a contact material is; it shall not cause sulphurization in hydrogen sulfide (H2S) exposure, and it shall have the electrical characteristic of 3micro(ohm)cm electrical resistivity and 10m(ohm) contact resistance or less. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 459-464 不均質系アパタイトの合成設計と生体材料への応用 Synthesis Design of Heterogeneous Apatite and Its Application to Biomaterials 岡崎正之　高橋純造　花村泰治　寺岡文雄　平雅之　前田芳信大阪大学歯学部 M. Okazaki, J. Takahashi, T. Sohmura, F. Teraoka, M. Taira and Y. MaedaOsaka UniversityFaculty of Dentistry  In the biological system, technically speaking, hydroxyapatite Ca10(PO4)6(OH)2 which constitutes teeth and bones is carbonic acid apatite which contains small amount of various ions and small percentage of CO32-.  CO32- content would differ in enamel, dentin, as well as bones, and locally observed, they would consist of the heterogeneously graded carbonic acid apatite containing different kinds of CO32-. Additionally, it is supposed that a gradient of F concentration exists from the surface layer of the enamel toward the internal layer, as well as the formation of fluoridated apatite in which the degree of fluoridation naturally differs.       We are advancing a research to find out the generation mechanism of such heterogeneous system apatite from a physiochemical standpoint. Our original 2-step supply system was devised in order to easy carry out the analysis by simplifying the phenomenon as much as possible. In this study, first of all, we will confirm the extent of crystallinity to which the research result of these heterogeneous system apatites can be applied, and then, by developing this system, establish the design guidelines which would control the synthesis of the apatite crystals with a highly functional gradient. In addition, on the basis of the basic research result, we intend to further research the hybrid biomaterial with the graded crystal structure from the surface to the internal layer, which is internally stable and externally metabolic, contacting well with the bone, so as to biochemically clarify the mechanism of the organism adhesion.       In this study, adopting the originally devised synthetic method by the 2-step system, 2 kinds of fluoridation apatite (H-FAp, F-HAp) were synthesized by changing the F supply, which stoichiometrically corresponds to the fluorapatite, in the first half and the latter half of the synthesis. In addition, a synthesis under the carbonate ion existence was also carried out. For the obtained apatite crystal, the solution property was examined while X crystallography examination was also conducted. Japanese 平成８年度科学研究費補助金重点領域研究領域番号　２７４「傾斜機能材料物理・科学」研究成果報告書平成９年３月 FY 1996 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1997  2 1997-03-01 465-474 光反応を用いた微細領域での傾斜機能高分子表面の作成と細胞機能発現の制御 Preparation of Functionally Gradient Polymer Surfaces with Micron-Order Precision using Photochemical Reaction and Cellular Responses 中山泰秀・松田武久国立循環器病センター研究所、生体工学部 Y. Nakayama, T. MatsudaNational Cardiovascular CenterResearch Institute　Department of Bioengineering  Biocompatibility of medical devices such as transplanted artificial organs is greatly dependent on the chemical composition and structure on a cellular level in polar surface of the medical materials which directly contact blood or organism.  However, due to the above-mentioned technical and theoretical problems, the practical application of radical polymerization to the modification of devices such as artificial organs has not been carried out.       In the early 1980's, Otsu et al. synthesized dithiocarbamate derivatives as an optical radical polymerization initiator of a new type and they reported that in case this initiator is used, the photopolymerization of vinyl monomers such as methyl methacrylate (MMA) and styrene (ST) progressed in appearance by the living radical polymerization mechanism, and that the control of the radical growth was possible. This dithiocarbamate derivative is named iniferter. When light is projected to benzyl N,N- diethyldithiocarbamate (BDC), one of iniferters, benzyl radicals and dithiocarbamate radicals are formed. The growth end, that has stopped the polymerization by the recombination with the dithiocarbamate radical, dissociates radicals again by the irradiation, and thus the polymerization is repeated.       The main purpose of this Scientific Research is to establish a fine structuring technology of the polymer surface and to produce the functionally graded polymer surface in the minute region on a cellular level. It intends to observe the cellular response behavior on the produced base material so as to produce functionally graded polymer substrate which can control the cellular functions (such as adhesion, extension and proliferation capability). In the first year, the basic processing technology for making this functionally graded polymer surface was developed. Specifically speaking, using the photoreactivity of BDC mentioned above, the precise three-dimensional control (XY plane, Z-axis height) of the surface graft polymerization was examined, which enables the control of the modification position, graft density and graft length of the mold-processed device.       To begin with, the BDC unit was introduced into the substrate surface by applying photoreactive polymers with BDC unit on the side-chain or chemically fixing the BDC unit on the surface. The photographing polymerization of various vinyl monomers was conducted on this substrate. The progress of the polymerization was observed in situ using the rock crystal vibrator sensor (QCM) which can detect and interpret a hyperfine mass change on a nanogram level as a resonant frequency change, and the polymerization of monomers was compared. In addition, the possibility of the precise fine processing by the photographing polymerization was examined. Japanese