# Fileset [kakenhi-1997-141-280.xlsx](https://mdr.nims.go.jp/filesets/0dc05b37-e1f2-4b33-ae4e-d84eed8fa9ea/download) ## Creator National Institute for Materials Science ## Rights ## Other metadata [FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274 Physics and Chemistry of Functionally Graded Materials Research Report (pp.141-280)](https://mdr.nims.go.jp/datasets/ad7ba5e3-107b-4f00-988d-59ddee4aa4f3) ## Fulltext Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 141-144 複合積層化合物を利用したナノスケール磁気傾斜機能材料の開発と物性 Preparation and Properties of Nano-scale Magnetically Graded Materials using Composite Layer Compounds 鈴木和也、道岡千城横浜国立大学　工学研究科 Kazuya Suzuki and Chishiro MichiokaGraduate School of Engineering, Yokohama National University When functionally graded thin films are made thinner, they are called ultimately thin functional films in which some kind of function is hoped to work by controlling the composition of the material in atomic layer scale. We choose the layer compound (MS)x(TS2)x that has alternate stacking structure of MS and TS2 in order to study the fundamental properties of functional atomic layer. 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 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. Last year we have studied the synthesis and properties of Fe intercalated (MS)1.19(TiS2)2 in the passed and found that in (CeS)1.19 [Fe033(TiS2)2] magnetic order of Ce and intercalated Fe both developed in the different temperature, antiferromagnetic for Ce and ferromagnetic for Fe, respectively. The magnetization curve of (CeS)1.19 [Fe0.33 (TiS2)2] indicates that nine different magnetic states can be attained within the external field of O. 3T, where the magnetic states are formed of the combination of the metamagnetic states of Ce and ferromagnetic states of Fe. In this report, we focused on novel compounds (MS)1.20CrS 2 and (MS)x[Fe0.33(NbS2)2] (M=La,Ce). The former compounds consist of magnetic Cr atoms in triangle arrangements in the crystal. The interatomic distances of Cr and M are much shorter than that of Fe-M in (MS)1.19[Fe0.33(TiS2)2] so that significant magnetic interaction is expected between the magnetic moments. In the latter compounds it is expected that the antiferromagnetic interaction works among Fe atoms that form triangle arrangement within the layer. The magnetic moments align in the stacking direction so that the very strong frustration may be possible to appear. We have investigated synthesis and electrical, magnetic and thermal properties of these compounds. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 145-148 DCアークプラズマ法による強磁性鉄窒化物膜の傾斜設計 Graded Design of Ferromagnetic Iron Nitride Film by DC Arc Plasma Method 山本直一冨井洋一花田禎一京都大学　大学院　人間・環境学研究科京都大学　大学院　エネルギー科学研究科京都大学　総合人間学部 Naoichi YAMAMOTO, Youichi TOMII, Teiichi HANADAGraduate School of Human and Environmental Studies, Kyoto University Graduate School of Energy Science, Kyoto University Faculty of Integrated Human Studies, Kyoto University Phase diagram (Fig. 1 by R. H. Jack) shows three kind of iron nitride compounds exist at room temperature as stable phases, that is (gamma)' -Fe4N, (epsilon)-FexN(20) and anti-ferromagnetic interactions (J<0) are mixed to form a new type of molecular-based magnets, in order to study the magnet's physical properties such as spontaneous magnetization, Curie and Weiss temperature, coercive force. We have chosen Prussian blue analogs, the oldest known metal complexes as the model materials. These have been widely used as ink materials and there are more than 100 analogs of these complexes, each of which displays different coloring pattern according to the metal ion it contains. When there is a combination of right paramagnetic ions, these analogues can also possess ferromagnetic properties. It has been found that V[Cr(CN)6]0.86 has very high magnetic phase-transition temperature for a molecular-based magnet, up to 315K. In the series of our works, we are trying to add new physical properties and functionality to Prussian blue analogs by the strategy to incorporate three (instead of usual two) types of metal ions. The first example along this line that we reported last year was the compounds in the series of mixed ferro-ferrimagnet (NixMn1-x)1.5[Cr III (CN)6]powders in which ferromagnetic NiCr and ferrimagnetic MnCr were mixed on the atomic level. Moreover, in a mixed ferro-ferrimagnet (FexMn1-x)1 .5[Cr(CN)6] powder, we have succeeded in demonstrating a novel photo-induced magnetic pole inversion. In the present work, in order to study the functionally graded magnetic properties of such ferro-ferrimagnets, we fabricated the novel types of magnetic thin films composed of a gradient composition between ferromagnetic and ferrimagnetic components by a simple electrochemical method. The film was transparent but exhibited different colors by controlling the proportion of the mixed components and the electric potential. We report here the magnetic properties of this novel functionally graded material. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 165-168 低次元発光材料の傾斜機能の研究 Study on the graded function 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 The self-activated luminescence of ZnGa204 with spinel structure has been studied. Recently, we found that ZnGa204 solid solution exhibited a full colored (white-emitting) phosphor if the solid solution consisted of the suitable graded compositions. The change in luminescence color was due to the change in emitting photon energy of donor-acceptor recombination center. The photon energy depended upon the band gap, which was determined from the absorption edges of solid solution. Also, the thermoluminescence (TL) occurred at the activated ions, giving rise to the luminescence characteristic of transition metal ion such as Mn2+ and Cr3+. The spinel structure consists of a f.c.c. anion sublattice that has half its octahedral interstices and one-eight of its tetrahedral interstices occupied by cations. Therefore the site preference of replaceable cation was governed luminescence characteristics. Simultaneously the decay profile of luminescence was changed by the partial replacement of aliovalent cation. Additional change, i.e. the formation of vacancies was needed to preserve electroneutrality. The present study was focused on identifying the experimental parameters which was required to make the full-colored or white-emission of ZnGa204 phosphor with graded and non-stoichiometric composition. Also, the improvement of thermoluminescence of ZnGa204 relatives was examined on the viewpoint of cystallographic low-dimensionality. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 169-172 キャリア濃度傾斜熱電半導体単結晶の熱電特性の研究 Studies on thermoelectric properties for thermoelectric semiconducting single crystals with FGM structure 海部宏昌東京都立大学　大学院工学研究科　電気工学専攻 H. T. KaibeGraduate School of Engineering, Graduate Course of Electrical Engineering, Tokyo Metropolitan University The possibility of improvement in thermoelectric performance for n-type PbTe with graded carrier concentration has been investigated since last year. The hot-pressed compact with three-stage structure was prepared and this 3-stages FGM had 10% larger output power when lower temperature is 500K and temperature different is 270K than that of each constituent. And also, the liquid phase diffusion bonding technique, which is available for the ingot materials, has been established. However, the single crystal of the thermoelectric materials, such as PbTe has not been obtained yet in this project. Then, the sublimation method was applied in order to grow the single crystals of n-type PbTe. The crystal growth from gas phase has superior crystalline to that of from melt phase. The improvement of the crystalline was thought to result in the elevation of the thermoelectric performance due to the increase in the carrier mobility. The sublimation method is also useful to fabricate FGM thermoelements with a graded carrier concentration by changing the starting material. Generally, the chemical transport technique which is one of the method of crystal growth from gas phase uses halogen compounds as agent material. In case of PbTe, halogen compounds act as n-type dopant, too, so with those compounds acting as both agent and dopant, controlling carrier concentration of growing crystalline should be easier. The knowledge concerning the growth direction and growth mechanism is considered to be strongly useful for the joining the dissimilar materials. This year, we have also tried to fabricate p-type PbTe-SnTe thermoelement with FGM structure and then evaluated how the graded structure affected its material's parameters. Furthermore, the liquid phase diffusion bonding using insert metal, Pb-60mass% Sn eutectic alloy film (50micrometers thick) was applied to join Pb0.75Sn0.25Te and Pb0.5Sn0.5Te, and the electrical and thermal properties of the bonded material was investigated. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 173-176 機能傾斜化CuInSe2系薄膜太陽電池 Functionally Graded CuInSe2 Thin Film Solar Cells 伊藤太一郎、小見崇、伊崎昌伸＊、芦田淳大阪府立大学工学部、＊大阪市立工業研究所 Taichiro Ito, Takashi Omi, Masanobu Izaki * and Atsushi AshidaOsaka Prefecture University, *Osaka Municipal Technical Research Institute CuInSe2 chalcopyrite-type compound semiconductor has attracted keen attention to apply as the absorption layer material of advanced high efficiency polycrystalline thin film solar cells. It is most desirable that CuInSe2 thin film as an optical absorption layer in a solar cell has (112) preferred orientation. Because, it is very remunerative terms for fabricating heterojunction with wide gap semiconductor thin film as window layer. On the other hand, CdS is employed as a material for high resistivity window layer in cells, because of ease of preparation, and ITO or ZnO is applied to transparent conductive layer. However, having many interfaces is disadvantageous in a solar cell in terms of efficient energy conversion. Furthermore, using Cd is undesirable. Therefore, using only ZnO in the form of n-type semiconductor for both the high resistivity window layer and low resistivity layer would unify the two layers without interfaces. To realize this, we tried to incorporate functionally graded layers in the thin film, namely, in the optical absorption layer, window layer and the transparent conductive material, and then to evaluate them. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 177-180 熱電複合傾斜機能構造材料における非従属的維持機構の研究 Independent Control of Thermoelectric Properties In MultiFunctionally Graded Thermoelectric Material 梶川武信湘南工科大学　工学部 T. KajikawaFaculty of Engineering, Shonan Institute of Technology Properties of sintered thermoelectric material are stipulated by the following four structure factors from macro to micro scale: 1) Chemical composition and formation of slid solution; 2) Morphology of hot-pressed compact, namely, polycrystalline, quasi-crystalline, mixed crystal, amorphous, porous, or thin; 3) Crystal structure, namely, band and electronic structure; 4) Composition and phase structure, namely, single- or poly-phase, grain boundary structure, particle profile distribution, and orientation. These factors have determinate effect on Seebeck coefficient, electrical conductivity, and thermal conductivity, the indicators of thermoelectric performance of the material. Moreover, addition of dopant may result in ionized impurities and formation of impurity level so as to affect carrier transport and scattering mechanism. In this study, we aimed to establish the fabrication technique of functionally graded thermoelectric material by controlling the gradient independent of structure factors by varying dopant concentration and hot-press condition. Thus it became apparent that the dopant concentration significantly affect carrier concentration and impurity scattering. Lattice defect and interface formation as results of varying hot-press condition can serve as carrier scatterer and source of supply. In the uniform molten thermoelectric semiconductor, when dopant concentration raises, Seebeck coefficient drops and electrical conductivity increases. However, the results of the experiments indicated it is possible to form a functionally graded thermoelectric material with a very different set of properties. In this research, antimony doped, sintered magnesium sliced made by spark plasma sintering has been studied. In the experiment the temperature dependence of Seebeck coefficient, electrical conductivity and Hall mobility were obtained for different sintering temperatures and dopant concentrations, and evaluation was made to see what determined those values with a view to enhance performance of the material at wider range of temperature. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 181-184 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・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, and Takaaki IshigureDepartment of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University/ Kanagawa Academy of Science and Technology Considerable research activity lately has been focused on the development of the optical component and devices that have the capability to support the high-speed multimedia network, with the information superhighway reaching. Mobile computing technology which enables people to reach the network wherever they are also calls for the research and development in this field. Since the conventional metallic cables in the access area network significantly limit the transmission rate to the order of kilobit per second, we have proposed a large-core, high-bandwidth, and low-loss GI polymer optic fibers (POF). These are inexpensive material fit for the order of gigabit per second transmission. Based on the theoretical analysis that has been made on their Bandwidth Characteristics, we have investigated ways to form a graded refractive index in the fiber so as to optimize the fabrication process for the material to have the best of properties. The fabricated material was then studied to measure the actual refractive index distribution profile to calculate modal dispersion in the material, so as to obtain the material's impulse response. When this calculation method was established, we were able to accurately know the difference between the designed refractive index distribution profile as optimal and the actual distribution profile to use this knowledge for further improvement of the design of refractive index profile. The refraction index is graded by forming a graded dopant molecule distribution toward the radius direction of the fiber in the matrix polymer. This presents a possible problem caused by the dispersion of the molecules under high temperature, because when the distribution profile changes the transmission speed may be slowed. Thus thermal stability and long term reliability is also one of the important issues for the realization of POF network. We describe in this paper that the thermal and long-term stability of the GI POF strongly depends on the used dopant, and that the refractive index profile of the GI POF can be maintained through high temperature aging by selecting the suitable dopant. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 185-188 高分子安定化液晶による屈折率傾斜特性とその応用 Graded-Refractive-Index Properties in Polymer Stabilized Liquid-Crystals and their Applications 佐藤進秋田大学　電気電子工学科 Susumu SatoDepartment of Electrical and Electronic Engineering, Akita University Since the molecular orientations and electric and optical properties in the nematic liquid crystal (LC) cells can easily be controlled by applying a relatively low voltage, recently many investigations into their practical application have been carried out as inflat-panel-type display devices. Their optical properties such as effective refractive index can also be gradually changed from the value for an extraordinary ray to that for an ordinary ray, which is the characteristic that is not known in other optical materials. We have tried to make applications of tunable lens and prisms have been materialized in which the focal length of the lens-shaped cells and the deflection angle of the prism-shaped cell can be varied by applying an electric field across the cells. We also fabricated a LC microlens making use of the effects of a graded-refractive-index profile induced by an axially symmetric nonuniform electric field. However, they have a certain disadvantage, namely, the graded-refractive-index profile disappears when the applied voltage is removed. Recently, UV curable LC materials, which have a nematic phase at room temperature, have been synthesized and are receiving great attention as novel LC materials. They can be photo-polymerized by ultraviolet (UV) irradiation in a nematic phase while holding the molecular orientation state. It is possible to form a highly transparent microlens with a relatively large numerical aperture by applying an electric field to the microlenses made from both the UV curable materials and the LC cells produced with the use of hole-patterned electrode and then photo-polymerizing them by UV irradiation. This can be used as a fabrication technique of polymer with Graded-Refractive-Index Properties. However, the graded-refractive-index properties have been frozen and they can hardly be varied by an electric field unlike the case using the usual nematic LCs. It is expected, though, that by fabricating a composite material of nematic LC added with a small amount of UV curable LC, it is possible to form a novel optical device in which the graded-refractive-index properties retains when voltage application is removed, and when it is applied, the optical properties can be varied. Such a composite material should have the improved response properties too. This can be achieved by first applying the nonuniform electric field to have the reorientation of the LC molecules, and then UV irradiation so as to form a polymer network to stabilize the polymer. In this research project, we aimed to prepare such polymer stabilized LC cells with the graded-refractive-index profile using a mixture of nematic LC and a small amount of UV curable LC materials. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 189-192 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 ShiraiFaculty of Engineering, Saitama University We have aimed to apply the silicon-based thin films to solar cell systems, so we have tried to develop the fabrication process using high quality a-Si:H,(mu)c-Si:H and their related alloys (Si1-xGex,a-Si1-xCx) in low temperature and to improve the efficiency of the system by incorporating the graded composition and phase into it. we have also evaluated the effect of graded composition on photoconductive carrier transport and stress relaxation. In particular we have aimed to enhance the optical absorption efficiencies of infrared region above 800nm by: 1) fabricating a graded semiconductor film in which germanium composition is continually or locally graded in the direction of depth in the a-Si:H thin film; and 2) doping the steady-state plasma of dichlorosilane (SiH 2Cl2)/H2 with changing amount of the dopant, SiH4, continually to make Si films with the phase gradients from a-Si:H to (mu)c-Si:H toward the depth. To make such vapor phase epitaxy (VPE) by plasma-enhanced CVD (PE-CVD) successful as a way to form compositional gradient, it must be performed on some conditions. First is highly photoconductive a-Si:H, (mu)c-Si:H and their based materials (a-SiGe). Second is the no interruption of RF plasma by supplying the guest molecules such as GeF4, SiH4 in this study. This requires that the electrolysis efficiency by plasma should be much higher for the guest gas than for the host molecules (SiH4, SiH2Cl2). And the third is no additional defects formed by changing the flow of guest molecules for the purpose of making a graded distribution. Thus, the development of a novel fabrication technique using plasma technologies is required to overcome these difficulties. The present reports describes (a) the design and fabrication of thin films with compositional gradients in which germanium composition is continually or locally graded using a-Si1-xGex:H(F)(x=0-0.5) alloys and (b) of the Si films with the phase gradients from a-Si:H to (mu)c-Si:H toward the depth. The carrier transport properties were systematically studied in a-Si1-xGex:H(F)(O-0.5) gradient structures. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 193-196 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 and Satoshi WadaFaculty of Technology, Tokyo University of Agriculture and Technology One of the unique property seen in ferroelectric ceramics is photorestrictive effect. This is a combination of photovoltaic effect and piezoelectric effect. The photorestricive properties of PLZT and LiNbO3 ceramics have been well reported by several authors, and some applications have been designed such as photodriven motors and relays. However, there are three important obstructions to be overcome. 1) driving wavelength is limited to ultraviolet range, 2) small strain (1x10**-4) and 3) slow response (1 sec~). The authors have successfully shifted the driving wavelength up to 380nm by substituting the rare earth trivalent ions in PLZT. Of course, this is not long enough if laser beams are to be used as driving waves, but we have come to feel the solution of the first one of aforementioned problems is in sight. A piezoelectric material called RAINBOW (Reduced And INternally Biased Oxide Wafer) ceramics have attracted much attention. A RAINBOW ceramic is fabricated through a preferential reduction by heat-treating a ferroelectric ceramic (in the form of 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. The unreduced region shows the piezoelectricity and the coupling factor of the whole material is improved by the high conductivity caused by the reduction. In the present work, to solve the problems 2) and 3), we propose a preferential reduction of PLZT photorestrictive ceramics to be carried out to: A) Improve the electric to mechanical energy transformation rate by increasing the coupling factor and thermal strain, and to B) Improve the light to electric energy transformation rate and also the response rate by adding a graded conductivity. The aim of the present work is to develop an improved photorestrictive actuator which shows a high strain and a quick response. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 197-200 分子性傾斜配向を有する光伝導性液晶材料の光電特性 Photo-electric Properties of Photoconductive Liquid Crystals with Graded Molecular Alignment 半那純一　舟橋正治東京工業大学　工学部　像情報工学研究施設 Jun-ichi Hanna and Masahiro FunahashiImaging Science and Engineering Laboratory, Faculty of Engineering, Tokyo Institute of Technology Liquid crystals exhibiting self-organizing behavior based on weak intermolecular interactions are utilized for display devices owing to the optical anisotropy induced by the molecular alignment sensitive to the surface properties of the substrate and to applied electric field. This indicates that the liquid crystals are an attractive materials system in which we can expect new phenomenon and properties induced by a molecularly graded alignment. We paid attention to the functionalized liquid crystal which enjoys a bulk fluidity and self-organizing molecular alignment in order to create new sophisticated functionality materials, and we here report the very first synthesis of a photoconductive smectic liquid crystal, 2-(4'-Heptyloxyphenyl)-6-dodecyllthiobenzothiazole (7O-PBT-S12). It was demonstrated that 7O-PBT-S12 exhibits a fast hole mobility of 6x10**-3 cm2/Vs which is 10**3 times faster than that of conventional polymer based photoconductors. More recently, we have succeeded in the synthesis of a new photoconductive smectic liquid crystal, 2-(4'-octylphenyl)-6-dodecyloxynaphthalene (8-PNP-O12) which exhibits bipolar and fast electronic mobility of 6x10**-3 cm2/Vs for both electrons and holes. The aim of the present study is to investigate effects of molecularly graded alignment in photoconductive liquid crystal cells on photoelectric properties, and the physical properties that are unique in this material. In the first phase, the major effort will be made in establishment of the graded molecular alignment with the photoconductive liquid crystal. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 201-204 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 Characterization of Optically Linear/Nonlinear Functional 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. SakaiFaculty of Engineering, Nagaoka University of Technology FGMs are fundamentally different from conventional structures with uniform composition and mere multilayered structures. Graded functions and energy conversion using the FGMs can be considered as the pillar of the future development in designing new functional materials. Among these are the optical devices which can utilize waves of light to yield the maximum benefit possible, and even control the waves. There is a growing demand for the development of such optical functionally graded materials. Recently, we succeeded in fabricating transparent TeO2-based glass-ceramics and discovered that the glass-ceramics show a nonlinear second harmonic generation (SHG). Further, we proposed optically linear/nonlinear functional graded glass-ceramics in which alkali metal ions are graded. In materials with a gradient in optical nonlinearity, it is possible to convert light energy (SHG) and confine light, and it is considered that a graded structure itself is just like a device. In this study, we tried to fabricate new materials in which a gradient from crystallized fraction to glassy fraction is formed, instead of crystallizing the whole functionally graded material itself after its fabrication. Such new transparent graded glass-ceramics will lead to the fabrication of optical functional graded glass-ceramic fibers with a crystallized core showing SHG and with a glassy clad that does not show SHG. At the interface between the core and the clad, there would be a graded structure in which the extent of crystallization is graded. We will also try to prepare Er3+ or Pr3+ doped transparent glass-ceramics, leading to the fabrication of functional graded materials with optical amplification (Fig.1). The other advantage of using glass and glass-ceramic processing is that it makes the preparation of materials such as long fibers and optical waveguides easier. TeO2-based glasses with low phonon energies show various unique properties, and recently their optical nonlinearities have been extensively studied. To our best knowledge, the research on transparent optical functional graded TeO2-based glass-ceramics, however, has not been carried out so far. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 205-208 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 NakanishiResearch Institute of Electronics, Shizuoka University As the saying goes, "Seeing is believing." So the need for the information in the form of visible and moving pictures runs high in today's world. The focus of attention in the study of image sensor is to improve its performance, and particularly researchers aim for the sensors with higher resolution and higher sensitivity. However, resolution and sensitivity do not go hand in hand because as the resolution (or the number of pixels) is increased the size of the pixels will be reduced. Then, photons introduced in the photodiode area decrease. This leads to a degradation of a signal to noise ratio of the image sensor. So it is necessary to realize a photo-conversion device that amplifies photo-signals larger than 100% quantum efficiency without noise. When a photo-conversion film is stacked on top of the photo-signal reading circuit such as the conventional CCD (Charge Coupled Device), the sensor's numerical aperture can be almost 100%. Amorphous silicon (a-Si:H) is a suitable photo-conversion material to be stacked on CCD. The a-Si:H film can absorb the visible light efficiently because of its absorption properties very similar to those of human eyes, and it is compatible and joins well with the conventional CCD process. If a photocurrent can be amplified free of noise in the photo-conversion film, the image sensor can have very high sensitivity. Recently, we confirmed the occurrences of the avalanche amplification phenomena in the amorphous silicon p-i-n photodiode film that we fabricated. However, generally the avalanche process is intrinsically accompanied by the excess noise. To realize an excess noise free avalanche photodiode, the concept of the staircase avalanche photodiode with linearly graded multilayer structure is accepted. In this study, we report the characteristics of an a-Si:H/a-SiC:H staircase photodiode with linearly graded-gap multiplication regions. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 209-212 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、梶浦英亮、矢野哲也大阪大学　大学院工学研究科 Itsuo OHNAKA, Hideyuki YASUDA, Hideaki KAZIURA, Tetsuya YANOGraduate School of Engineering, Osaka University Thermoelectric materials have been extensively studied for the application to power generation systems with cooling and heating devises. Recently,it have proposed a new thermoelectric power generation systems using porous thermoelectric device. Unique features of the porous thermoelectric devices include: (1)The large and steep temperature gradient in the porous media, and (2)The hot side of the device being exposed to flames. Therefore the thermoelectric device is required to exhibit high thermoelectric power in a wide temperature range and to have resistance to oxidation at high temperatures. It is, however, difficult to meet these requirements by a single-phase materials. Functionally graded materials which satisfy the following requirement can achieve good thermoelectric performance. (a) Oxidation resistance at high temperatures (b) High performance in wide temperature range (c) Porous structure which causes optimum temperature profile In this study, our target is synthesis and development of porous thermoelectric devices by functional graded materials of oxidation resistance (chemical properties), thermoelectric properties and porous structure (physical properties). First of all, processing of porous media formation has been investigated, since few studies has been done for porous thermoelectric materials. 1. Production of porous materials (especially brittle materials like FeSi2, PbTe) 2. Synthesis of porous thermoelectric device for functionally graded materials 3. Evaluation of the porous thermoelectric devices For the first item, we tried to produce the porous devices were by a short-time laser irradiation of particles in solid-liquid state and hot press method including SPS method. Prototypes of functionally graded FeSi2/(Bi, Sb)2Te3 and FeSi2/PbTe porous thermoelectric devices were also produced. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 213-216 光増感反応を用いる高分子の光電気的機能の傾斜化 Fabrication of a 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 Yamashita and Yutaka HarimaFaculty of Integrated Arts and Sciences, Hiroshima University In the last two decades polymeric semiconductors have received significant attention as new functionality organic materials such as polyacetylene and polythiophene that are applicable to solar cells, light emitting diodes, batteries and so on. Establishment of a technology for fabricating a potential-graded phase in an organic semiconductor would be a desirable approach to the construction of new organic devices and improvement of their performance. That would include forming a graded p-n junction (called a p-n homo-junction) in one polymer film, or a gradient between p- (or n-) doping and de-doping in order to from a graded potential. Recently, we have used photosensitized oxidative and reductive reactions of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+), resulting in the intermediate product, [Ru(bpy)3]3+ or [Ru(bpy)3]+, to develop a new method for doping polymers and give it a graded potential. These intermediate products are then to be used as oxidative and reductive agent in anion (p-) or cation (n-) doping and dedoping. This process is called a photosensitized doping (PSD). In this report we also describe the modified PSD technique called the potentiostatic PSD (PPSD) method, in which the controlled-potential electrochemical doping and the PSD are combined. Using the potentiostatic PSD (PPSD) method a potential-graded phase in the direction of the thickness in a polymer film can be readily fabricated. In addition, we employed spin-coat to synthesize thin films from poly[sylanylene(oligothienylene)]s such as poly[(diethylmonosilanylene)penta(2,5-thienylene)] (MS5T), promising materials applicable to conductors and photoresists, etc., and studied those films' optical and electrochemical properties. We also investigated the application of the PSD method to anion (p-) doping and preparation of images on a thin film of MS5T. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 217-220 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 By controlling microstructures of thermoelectric sintered materials, it may be possible to form a microscopic functional structures at the grain boundary to minimize losses at the boundary, decrease the thermal conductivity and increase the Seebeck coefficient all of which result in the thermoelectrical performance of the materials. In this study, we have investigated the control of microstructures in thermoelectric sintered materials by the plasma powder treatment technique in order to improve their performance as thermoelectric converters from the semiconductor engineering point of view. Functionally graded structures can be formed at grain boundaries of sintered materials by sintering their raw powders of which surfaces are modified in reactive plasmas. This year we have studied the Si-Ge and Bi-Sb thermoelectric sintered materials. For the Si-Ge materials, the improvement of thermoelectric performance by the energy filtering effect has been investigated. To that end, SiGe powder was sintered after treating the grains with SiH4 to form a Si-rich layer with a greater bandgap than SiGe on the sintered grain boundary. For the Bi-Sb materials, the thermoelectric properties of sintered Bi have been investigated after treating Bi powder with Ar, H2, O2 and SbCl3+H2 plasmas. With each of these plasma treatments we aimed at various kinds of surface modification of Bi powder, that is, etching and/or deviating of surface Bi atoms by bombardment of Ar+ ions with the Ar plasma treatment, reduction of O on the Bi powder surface with the H2 plasma treatment, oxidation of the powder with the O2 plasma treatment, and Sb coating of the powder with the SbCl3+H2 plasma treatment. We also investigated the thermoelectric properties of sintered Bi-Sb alloys using their O2 plasma treated powder. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 221-224 生物を模倣した高分子傾斜材料の設計 Biomimetic Design of Polymeric FGM 小野勝道茨城大学　工学部 Katsumichi OnoFaculty of Engineering, Ibaraki University The main objective of A04 research group is to prepare FGM ranging nm to cm in size by chemical and biochemical reaction as well as to clarify the graded structure of various biological tissues. In order to control the size of the FGM structure, it is necessary that the reactant has an appropriate rate of mass transfer and that the reaction product is practically immobilized. Generally, we reduce the rate of mass transfer of the reaction product by quenching the reaction. In the case of biological tissue, the rate of mass transfer is reduced by the formation of immobilized products without quenching the reaction. In this study we analyzed a simple model system where the reactant having the diffusion coefficient D forms immobilized product by n-th order reaction. The condition for the formation of FGM is derived by analyzing the model system using theoretical and/or numerical calculations. The results were compared with experimental profile of graded structure. Finally we also discussed the control of the size of FGM and that of the distribution function of FGM to analyze the possibility of biomimetic design. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 225-228 人工生体構成材料の作製と応用－チタン／アパタイト、チタン／コバルト系傾斜機能型インプラントの生体親和性－ The Chemical and Biochemical Functionally Graded Materials Synthesis of Biomaterials and their Application - Biocompatibility of Titanium/Hydroxyapatite and Titanium/Cobalt Functionally Graded Dental Implants- 亘理文夫、横山敦郎＊、佐相史徳＊、宇尾基弘、松野浩宣＊、川崎貴生＊北海道大学　歯学部　歯科理工学講座、＊歯科補綴学第一講座 F. WATARI, A. YOKOYAMA*, F. SASO*, M. UO, H. MATSUNO* and T. KAWASAKI*Department of Dental Materials and Engineering, * Department of Removable Prosthodontics , School of Dentistry, Hokkaido University The present structure of dental implant, which is set in the jawbone with the form penetrating from the inside to the outside of the bone, is not necessarily the best form, where the whole part is composed of the single composition and uniform structure because different parts of the structure should be able to perform different functions. The dental implant with the structure of functionally graded materials (FGM), for example, with the composition from the biocompatible metal, Ti, at one end, gradually increasing the concentration of hydroxyapatite (HAP) ceramic toward 100% at the other end, could control the functions of mechanical properties and biocompatibility, depending on the necessity of each part of the implant, without the abrupt change by the formation of discrete boundaries. FGM of this type is expressed as Ti/100 HAP. To investigate the influence of FGM structure on tissue response, the animal implantation test was done and tissue reaction to the gradient composition were compared for Ti/2OHAP and Ti/100Co FGM implants as well as the pure metal implants of Ti, Hf, Nb, Ta, Re, Ni. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 229-232 植物の階層的傾斜構造 Functionally Graded and Hierarchical Structure of Plants 天田重庚、深尾守昭、孫運涛群馬大学 S. Amada, M. Fukao and Yuntao SunGunma University Plants have acquired various intelligent properties over a long period of time to adapt to the natural environment. One of those properties is hierarchical structure, or functionally graded structure. These lead to a generation of far superior function. Of all those plants bamboo must be a typical one because of its fiber reinforced composite. In the mechanical view point, it is anticipated that functionally graded structure has been established at each scale level. So far, the macroscopic functionally graded structure (the 1st functionally graded structure) on the bamboo shape and the microscopic one (2nd functionally graded structure) on the fiber distribution in the bamboo culm have been uncovered. The 3rd FGM structure is expected to exist in the wall structure of the vascular bundle sheath (simply called fiber) surrounding the vessels and sieve tubes. This report presents the measurements of the elastic property on fibers based on the non-destructive approach using a scanning acoustic microscope (SAM), which is concerned with the 3rd FGM level. Also the fracture toughness of the bamboo culm is discussed, which is in the 2nd FGM level. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 233-236 生体活性傾斜機能材料の設計 Design of Bioactive Functionally Graded Materials 小久保正京都大学　工学研究科 T. KokuboFaculty of Engineering, Kyoto University Some ceramics come into direct contact with living bone without forming the fibrous tissue around them and form strong chemical bondings with the bone. Bioglass (registered trademark), sintered hydroxyapatite and glass-ceramic A-W are its examples. They are now called bioactive ceramics, and already clinically used as valuable bone-repairing materials. None of the bioactive ceramics, however, can be used as implants to replace highly load-bearing bones, since their fracture toughness is low. Some metallic materials such as Ti metal coated with hydroxyapatite by plasma spraying method are currently used as load-bearing implants. However, the control of crystallity and composition of the coated hydroxyapatite and its strong adhesion to the metal substrates are very difficult. Recently, the author showed that a simple NaOH and subsequent heat treatments give a bioactive titanium (Ti) metal, where a sodium titanate graded structure is formed on its surface. Thus treated Ti metal spontaneously bonds to bone via the formation of bonelike apatite layer on its surface in the body as the bioactive ceramics do. In the process of apatite formation, a graded structure is established at the apatite-metal interface to provide tight integration of the metal with the bone. In the present study, Ti-6Al-4V alloy metal, which is more often used as load-bearing orthopedic and dental implants, was subjected to the NaOH and heat treatments to investigate whether the graded structure of the same kind with the one mentioned above can be formed on its surface and how the graded structure changes in body fluid environment. Aluminum (Al) is reported to suppress the apatite formation, and vanadium (V) is toxic to the living body. It is therefore very important to clarify how the Al and V constituting the alloy affect on the formation of the sodium titanate and apatite with graded structures for clinical application of this kind of bioactive alloy metals. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 237-240 植物における傾斜機能構造の発現機構 Adaptive Growth Mechanisms of Design Architecture of FGMS in Plants 野方文雄姫路工業大学　工学部・機械工学科 F. NogataDepartment of Mechanical Engineering, Himeji Institute of Technology Animals and plants have acquired their shapes, exquisitely subtle design of tissues and graded and/or hierarchical structures through a long period of continuous and repeated adaptation and optimization. Living organisms therefore display attractive features for the industrial material engineers to learn from, such as basic microstructures as building units of hard tissues, their functions, and self-renewal power. This is the idea underlining the new concept called biomimetics, as biomaterials can be a source of limitless ideas. When we consider from the standpoint of mechanical engineering the reason why the living things we see around us were able to win severe competition for survival with minimum materials and limited space, we can easily see that they have developed the stiffest possible materials of minimum weight (Matteck, 1990). One of the fundamental difference between biomaterials and artificial materials is that the former possess multifunctional and hierarchical structures for environmental adaptation (Srinnivasan et al., 1991) which result in complicated and heterogeneous functionally materials. In this study, as the long-term goal we purposed first to understand the designing principle found in the biomaterials and shaping mechanisms, and then to perform biomimetic designing for the development of frontier materials with new functions and structures while adjusting the newly gained knowledge to fit the different applications. In this report, we discuss the growth mechanism from the new findings on electrical signals in the living plant cells. It has been found that the biological electric signal from the cells of plant controls the growth activity. Thus it was demonstrated that we can control the structures of biomaterials using specific electric signals. This was confirmed by artificially controlling the self-optimizing, cell-based sensing system for analyzing external physical stimuli adapted by plants, which resulted in arbitrary shape control. This cell-level observation could serve as a useful model to understand how intelligent, multiphase/graded materials are developed in the living systems. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 241-244 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構 Graded Composition of Stable Rust Layer of Cr substituted Goethite Formed on Weathering Steel and Suppression Mechanism on Atmospheric Corrosion 三澤俊平室蘭工業大学　工学部　材料物性工学科 Toshihei MisawaDepartment of Materials Science and Engineering, Faculty of Engineering, Muroran Institute of Technology Weathering steels have high atmospheric corrosion resistance by the presence of stable rust layer. On the basis of analytical results of rust layer of a weathering steel which exposed to atmosphere in an industrial area for a quarter of century, it was found that final stable rust layer of the weathering steel had a Goethite structure of (alpha)-FeOOH type and Cr containing condensely packed (alpha)-(Cr1-x,Fex)OOH(Cr substituted Goethite) grains are gradually distributed in the rust layer. In seashore region, permeation behavior of chloride ions through rust layer influence corrosion of weathering steels greatly. Current flow from anode to cathode is carried by the transport of ions which pass through the rust layer and electrochemical corrosion is controlled by the layer's ion selectivity. Although main component substances in the rust layer on weathering steels are composed of various iron oxyhydroxides, their ion selective properties are not fully understood. In this paper, ion selectivity of iron oxyhydroxides and iron oxides were investigated by the measurement of electrochemical ion selectivity of rust layer which is its important function. Furthermore, effect of Cr content gradient and adsorbed oxyanions on the ion selective properties of (alpha)-(Cr1-x,Fex)OOH were examined. On the basis of the results, the protection mechanism for the stable rust layer formed on weathering steels was discussed. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 245-248 イネ科植物の茎の構造と組織形成における傾斜構造の解析 Analysis of graded structure of stem in Graminaceous plants 高橋清、後藤雄佐、中村貞二東北大学　大学院農学研究科 K. Takahashi, Y. Goto and T. NakamuraGraduate School of Agricultural Science, Tohoku University Amada et al (1996) reported that two kinds of graded functions were found in the Graminaceous plants such as bamboo tree. One of them is the micro structure in the transverse section of the stem which may have the protective function from the outer stress. The other is the macro structure which is shown in the interval of the nodes, along the length of the internodes. The latter may have the role to support the very high stem. As a result, the stem of Graminaceous plants is not so heavy despite its length. Last year we observed the process of the formation of graded structure in the internode along the lengths using the sweet sorghum, a graminaceous plant with stuffed nodes, and also in the transverse section of its stem. Especially the density of the vascular bundles was the highest in the surface area (periferal zone) and was the lowest in the central area (pith). On the other hand, the size of single vascular bundle was the smallest in the peripheral zone and the largest in the pith. It was already reported that auxin, one of the plant hormone, has an important role in the formation of vascular bundles. It is also known that auxin is produced in the shoot apex and it moves downward as described as polar transport. High concentration of auxin stimulated differentiation of vascular bundle whereas the size of a vascular bundle became smaller, and low concentration of auxin has the reverse effect of suppressing the differentiation and result in bigger vascular bundles. Therefore we suggested that auxin may have a role in formation of the graded structure in the vascular bundle of the sweet sorghum. This year we investigated the distribution of silica (SiO2) in the rice plant because a graded distribution pattern of silica was found in the preliminary experiments. It was also reported that large amount of silica exists in rice plant and the silica played a role as a physical support and protect from the attack of fungi such as rice blust. In the present report we measured the accumulation of silica in the stem of the plant, and discussed possible factors that governs its graded distribution. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 249-252 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 ItoDepartment of Chemistry, Graduate School of Science, Tohoku University A triruthenium cluster complex of the type [Ru3((mu)3-0)((mu)-CH3CO2)6(L)3]+ shows reversible 4 step 1 electron redox waves. It is possible to make oligomers by linking the trinuclear complex with bridging ligand such as pyrazine or 4,4'-bipyridine. Since each Ru3 unit in oligomer shows respective redox waves, it is expected to make electrochemical potential slope along the oligomer chain by arranging appropriate terminal ligands in the oligomer. Objectives of the present study are : (1) to make such Ru3 oligomers with electrochemical potential slope; (2) to investigate the relation between the electrochemical potential slope and the rate of electron transfer along the chain. In the last fiscal year, in an effort to reach the goal (1), we succeeded in preparing several such oligomers (Fig.1), and confirmed the formation of the electrochemical potential slope by means of cyclic voltammetry and other quantitative measurements. In this fiscal year, we started the research aiming at the objective (2). To that end we selected a series of Ru3 dimer shown, in which each unit has carbonyl ligand. The reason why we selected this series of compounds is based on extensive electrochemical studies on various Ru3 dimers to seek an appropriate compound system for this research purpose. Preliminary experiments indicated that it is possible in this kind of dimers to change the extent of inter-unit interaction, that is, intermolecular electron transfer rate over a wide rage by the right selection of bridging and terminal ligand. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 253-256 濃度傾斜表面の作成と表面反応性制御およびXPEEMシステムの開発 Preparation of the concentration graded surface and development of XPEEM imaging system for surface reaction control 朝倉清高東京大学　理学部　スペクトル化学研究センター K. AsakuraResearch Center for Spectrochemistry, Faculty of Science, The University of Tokyo Regulation of surface chemical reactions is possible by controlling the self-organized chemical waves created on the surface. In this study, we tried to regulate the propagation direction of the chemical waves by using the concentration or temperature graded surface. For this purpose, we developed a new characterization tool for the graded surface called as XPEEM(X-ray photoemission electron microscopy). XPEEM is a technique combining PEEM(Photoemission electron microscopy) and XPS(X-ray photoelectron spectroscopy). PEEM gives the real time imaging of the surface using the dependence of photoelectrons on the difference in the work function of surface in-situ under the reaction conditions. The XPS makes the analysis of the surface elements possible. Thus XPEEM is the method to obtain mapping of the element distribution of the surface under reaction conditions. We have developed XPEEM system as described to clarify the structure of concentration-graded surface and its effect on reaction waves. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 257-260 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　水野一乗　広瀬志弘　中里浩一　吉川究　小杉浩章東京大学　大学院総合文化研究科　生命環境科学系 T. Hayashi, K. Mizuno, M. Hirose, K. Nakazato, K. Yoshikawa, H. KosugiDepartment of Life Sciences, Graduate School of Arts & Sciences, The University of Tokyo The infrastructure of living organ and tissue has a graded structure of various collagenous supramolecular structures as skeleton. The epithelial or endothelial cells are surrounded by supramolecular matrix made of a network structure of thin filaments. Filaments closest to the cells are thinnest, and the further the distance from the cell the thicker the filaments become because they start forming clusters. This might be called a graded filaments structure with a thickness gradient. The immunohistochemical analyses suggested the graded distribution of different molecular species of collagen, with diameters increasing as described above. Our results are summarized in Fig. 1a as a hypothetical general skeletal structure of tissue. The model can be combined to form further complex structures in Fig. 1b. In blood vessel wall, type IV collagen, type V collagen, type III collagen and type I collagen (with diameters increasing in this order) are found in accord with the graded distribution of vascular endothelial cells, vascular smooth muscle cells and fibroblasts. Apparent correlation of the graded distributions of cell types and collagen types may be involved in maintaining the tissue homeostasis and multicellular functions. In a trial of building an experimental system to test this possibility, we decided to investigate the cellular behavior and responses when cultured in the matrix (the culture substrate) in which a graded collagen structure is formed. In this research program we aim to isolate each type of collagen to reformation different collagen supramolecular structures in the culture substrates to see how the matrix structure affects cellular proliferation and differentiation. We here report the result of cell culture using the type IV collagen gel that we successfully carried out for the first time in the world. It showed quite unexpected and interesting influences on cells. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 261-264 歯質とポリマーとの傾斜機能型分子複合体の合成と接着機構の解明 Preparation of a Molecular Level Composite Having Concentration Gradient in Dentine Side with Copolymers and Analysis of the Bonding Mechanism of Copolymers to Dentin 中林宣男　石原一彦　渡辺昭彦東京医科歯科大学　医用器材研究所 N. NAKABAYASHI, K. Ishihara and A. WatanabeInstitute for Medical and Dental Engineering, Tokyo Medical and Dental University Medical and dental treatment with the use of artificial materials are called for when spontaneous regeneration cannot be hoped for, as in the case of lost tooth or teeth. Therefore the bonding technique is very important in dental treatment, especially because of tentimes infection at the interface have caused the recurrent caries and eventual permanent loss of the tooth or teeth. A new idea occurred that monomers with hydrophilic group (reactive with hydroxyapatite) and hydrophobic groups might be effective on the adhesion without chemical reactions. We started synthesizing compounds with both hydroxyl (hydrophilic) groups and hydrophobic groups. These compounds are called methacrylates and they had no possibility of forming chemical bonding and tested their mechanical bonding. It meant that the rate of curing must have important influence on the adhesion and this adhesion might not take place by simple interfacial attachment. Adhesion should not be done on the surface of the tooth substance, and polymeric curing is needed after the diffusion of monomer into tooth substance. Hydorophobic and hydrophilic groups of monomer may help monomer to diffuse into tooth substance.With regard to the adhesion to dentin, it was clear that a new resin infiltrated dentin was formed on the dentin's surface layer by diffusing monomer on the decalcified dentin surface layer and curing the diffused monomer. It was found that it was possible to join polymer and dentin reproductively through resin infiltrated dentin. It became obvious , as results of various kinds of analysis, that resin infiltrated dentin is neither dentin nor polymer, but mixed structure of the both at the molecular level. Material scientific speaking, it can be said that resin infiltrated dentin is one of functionally graded materials synthesized by monomer diffusion and curing. The existence of concentration gradients in the composition on dentin side of jointed interface means quick change of composition does not occur in the interface between different materials. Therefore, fraction from the interface due to stress concentration does not likely develop even if the interface between resin infiltrated layer and polymer is loaded. This function can be thought advantageous for bonding of body and artificial material. It is also advantage that resin infiltrated dentin is collagen fiber- reinforced polymer. Modern dental treatment has been more likely to destroy body tissues and replace them with artificial dental materials. However, we feel that dental treatment will finally change to the one without destruction of biological structure. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 265-268 DNA二重らせん鎖の配向固定化傾斜機能フィルム Functionally Graded Films With Fixed DNA Double Strands Alignment 岡畑恵雄東京工業大学・生命理工学部 Yoshio OkahataSchool of Bioscience and Biotechnology,Tokyo Institute of Technology DNA is a source of genetic information, but it is also interesting as a molecular material that shows a long double helical structure intercalated with flat molecules in-between base pairs; and therefore is a good candidate for electron conduction materials. DNA has mainly hydrophilic groups so it is usually treated in the form of aqueous solution or powder, but if it can be made soluble in organic solvent, or have its double helix aligned in one direction to be made into a film, it can also be a candidate for functionally graded material. In this report, we describe two methods to prepare organic thin films in which DNA strands aligned in one direction by i) uniaxial stretching of a cast film of DNA-lipid complex by making cations that unite with anion phosphate of DNA into cationic lipid, and ii) vertical dipping LB method of anionic DNA strands with cationic lipid monolayers. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 269-272 光ダイナミックスによる無機層状空間の可逆的変化 Reversible Changes in Space Between Inorganic Layers By Means of Photodynamics 高木克彦　志知哲也　小木曽博貴名古屋大学 大学院工学研究科 Katsuhiko Takagi, Tetsuya Shichi, and Hiroki OgisoGraduate School of Engineering, Nagoya University Clay minerals exhibit an intercalation capability to adsorb various organic guest molecules on their layer surfaces by ionic exchange. The amount of adsorption is defined as the cation-exchange-capacity (CEC); thus, in the case of intercalation by ionic exchange with the counterion, the amount of guest molecules can be controlled by the CEC of the clay. For instance, montmorillonite clay can accommodate stilbazolium cations quantitatively up to the CEC of the clay, but over the CEC, the adsorption sites are saturated and the amount of guest cations levels off. A typical montmorillonite clay, Kunipia F, is known to possess, on average, approximately one exchangeable sodium cation molecule per 100 square A. Therefore, judging from the estimated cross-section area of the molecule which is much larger than 100 square A, it is unlikely that a dense packing of the stilbazolium ions on the surface of the clay can be attained, which is in contrast to the molecular packing observed in typical organic crystals and LB membranes. In order to fully utilize organic-inorganic hybrid materials including functional guest molecules in clay, it is vital to construct clay interlayers which is as densely packed with the aggregates of the guest molecules as possible. In the present investigation, we have undertaken the task of realizing a method of obtaining the closest packing as possible in the clay by the intercalation of guest molecules far exceeding the CEC. By employing such procedures, we have presented a new methodology for the enhanced intercalation of zwitterionic guest molecules. These adsorption characteristics explicitly reflect the grated functionality between the intercalated guest molecules and the added molecules in a range of up to ca.400% based on the CEC of the clay. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 273-276 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 Apatites and Their Application to Biomaterials 岡崎正之　高橋純造　荘村泰治　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. MaedaFaculty of Dentistry, Osaka University Apatite formation occurs sometimes heterogeneously in some biological systems. To investigate such heterogeneous precipitation phenomena in biological systems, we are continuing our synthesis experiments. Fluoridated hydroxyapatites were synthesized heterogeneously using a two-step fluoride supply system. Two different types of heterogeneous fluoridated apatites were formed: hydroxyapatite covered with fluorapatite, and fluorapatite covered with hydroxyapatite. There are various fluoridated apatites with different degrees of fluoridation (the degree of fluoridation X=0: hydroxyapatite, X=1.0: fluorapatite). In this study, heterogeneous fluoridated hydroxyapatites were synthesized with various fluoride concentrations equivalent to those from hydroxyapatite to fluorapatite. In addition, a three-step fluoride supply system was also adopted for apatite synthesis. Furthermore, in human teeth the negative gradient of fluoride concentration from the surface of tooth enamel toward dentine-enamel junction can be formed. We speculate that even each crystal composing enamel layer may have a distribution. Therefore, we newly created a continuous gradient fluoride supply system by developing the previous step-like fluoride supply system in this study. Japanese 平成９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１０年３月 FY 1997 Grant-in-Aid for Scientific Research on Priority Area, No. 274Physics and Chemistry of Functionally Graded MaterialsResearch Report March 1998 1 1998-03-01 277-280 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 and T. MatsudaDepartment of Bioengineering, National Cardiovascular Center Research Institute, Since the surface structure, composition and properties at the outermost layers of blood- or tissue-contacting surfaces determine the biological responses to biomedical devices, surface design in the devices is crucial with regard to whether implanted devices can be accepted or rejected by body defense mechanisms. Both nonionic hydrophilicand hydrated surfaces are generally considered to be resistant to both protein adsorption and cellular adhesion, while hydrophobic or ionic surfaces are thought to promote protein adsorption and cellular adhesion, spreading, and proliferation. Within a single device, there may be several different local microenvironments, each with its own set of requirements for efficacious cell-material interactions. Thus, there is considerable impetus to develop regionally specific, multifunctionalized surfaces for the purpose of studying these localized cellular interactions. Last year, we developed a surface modification technique that enables the generation of graft-polymerized surface with micronorder regional precision. The technique is based on photochemistry of benzyl dithiocarbamate 'iniferters' (Figure 1). Since the reaction proceeds only during photoirradiation and at photoirradiated regions, the reactive zone can be easily controlled using a photomask. Using surface photo-graft copolymerization via benzyl N,N-diethyldithiocarbamate free radical chemistry, we have deposited hydrophilic nonionic regions on hydrophobic biomedical polymers. In this year, we prepared three different three dimensional photo-grafted gradient surfaces, and then exampled the endothelial cell adhesion and proliferation on these surfaces. The gradient surfaces allowed a controlled examination of the effect of polymer chain length on the cellular response within one physical sample. With these novel surfaces, the initial studies involving the simultaneous characterization of the cellular response in multiple microenvironments have been completed. Japanese