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National Institute for Materials Science

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[FUNCTIONALLY GRADED MATERIALS 1996 (pp.527-790)](https://mdr.nims.go.jp/datasets/2fb2d449-a477-4742-a403-456831f01ee1)

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Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 527-531 N型多結晶Bi-Sbの製造とその熱電特性 Fabrication of N-type Polycrystalline Bi-Sb and Their Thermoelectric Properties 宮島雅史a、G.G.Lee b、川崎亮 c、渡辺龍三 ca ダイキン工業株式会社MEC研究所、980-77 仙台市 東北大学工学部大学院生 b Korea Institute of Machinery and Metals, Changwon Industrial Complex, 66, Sangnam-dong, Changwon, Kyungsang-namdo, Korea c 東北大学工学部材料加工学科　980-77 仙台市 M.Miyajima a, G.G.Lee b, A.Kawasaki c and R.Watanabe ca Daikin Industries Ltd. MEC Laboratory, Graduate Student, Faculty of Engineering, Tohoku University, Sendai 980-77, Japan b Korea Institute of Machinery and Metals, Changwon Industrial Complex, 66, Sangnam-dong, Changwon, Kyungsang-namdo, Korea c Department of Materials Processing, Faculty of Engineering, Tohoku University, Sendai 980-77, Japan  We report on the powder metallurgical fabrication of bismuth-antimony solid solution and the thermoelectric properties of the fabricated composites. The solid solution powders were prepared by mechanical alloying (MA) aiming at large reduction of the thermal conductivity with the very fine microstructures obtained through MA process. The prepared bismuth-antimony powders (Bi-7.5at%Sb) have been sintered by hot pressing.      The thermoelectric properties of the sintered Bi-Sb compacts were influenced by the MA conditions. With the development of very fine grain microstructure, the thermal conductivity was reduced to the level of 2.0 W/mK which is about the 40% of the sintered compacts made from melt-solidified (MS) Bi-7.5at%Sb powder.      Summary      Bi-7.5at% Sb thermoelectric semiconductor powders were prepared by mechanical alloying. The following results were obtained.      (1) Bi-7.5at%Sb solid solution powders were successfully prepared by mechanical alloying.      (2) The sintered Bi-7.5at%Sb samples showed submicron size microstructure. The grain size varied with the change of milling time length in mechanical alloying process. And these difference in microstructure resulted in different thermoelectric properties. The figure of merit of the compacts from MA powders were better than that of the compacts of melt solidified and pulverized powder samples.     English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 533-538 PIES法による傾斜機能熱電材料の開発 Development of Functionally Graded Thermoelectric Materials by PIES Method 山本淳、太田敏隆通商産業省　工業技術院電子技術総合研究所　エネルギー基礎部 　305 茨城県つくば市梅園 1-1-4 A.Yamamoto and T.OhtaEnergy Fundamentals Division, Electrotechnical Laboratory, AIST, MITI, Umezono 1- 1-4 Tsukuba Ibaraki 305, Japan  An attempt was made to develop compositionally graded p-type Bi-Sb-Te thermoelectric materials by PIES (Pulverized and Intermixed Elements Sintering) - Hot Press method. The sample developed here consisted of three segments of different alloy composition. The electrical output of the sample under temperature difference of 200K showed an asymmetry with forward and reversed temperature gradient. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 539-543 熱圧により製造した p型 Bi0.5Sb1.5Te3 の微細構造および熱電特性 Microstructure and thermoelectric properties of p-type Bi0.5Sb1.5Te3 fabricated by hot pressing Doo-Myun Lee, Jun-Ho Seo, Kyeongsoon Park a, 塩田一路 b, Chi-Hwan LeeDept. of Metallurgical Engineering, Inha University, Inchon 402-751, Korea a Dept. of Materials Engineering, Chung-ju National Univ. , Chungbuk 380-702, Korea b 工学院大学環境科学工学科　192 東京都 Doo-Myun Lee, Jun-Ho Seo, Kyeongsoon Park a, Ichiro Shiota b, Chi-Hwan LeeDept. of Metallurgical Engineering, Inha University, Inchon 402-751, Korea a Dept. of Materials Engineering, Chung-ju National Univ. , Chungbuk 380-702, Korea b Dept. of Chemical Engineering, Kogakuin National University, Tokyo 192, Japan  The p-type Bi0.5Sb1.5Te3 compound doped with 4.0 wt% Te was fabricated by the hot pressing at the temperature range 380 to 440 deg.c under 200 MPa in Ar. The microstructure and thermoelectric properties of the compound were investigated. Optical microscopy, scanning electron microscopy, and X-ray diffraction were used to examine the microstructure. The microstructure was relatively dense. The density was increased with increasing the pressing temperature. The grains were preferentially oriented through the hot pressing and also the degree of preferred orientation was increased with the pressing temperature. It was also found that the figure of merit was increased with increasing the hot pressing temperature. The highest figure of merit (2.69x10**-3/K) was obtained at 420 deg.c. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 545-549 高温押し出し処理したp型Bi0.5Sb1.5Te3の微細構造および熱電特性 Microstructural and thermoelectric properties of hot-extruded p-type Bi0.5Sb1.5Te3 Jun-Ho Seo、Doo-Myun Lee、Kyeongsoon Park a、Jong-Hoon Kim b 西田勲夫 c、Chi-Hwan LeeDept. of Metallurgical Engineering, Inha University, Inchon 402-751, Korea a Dept. of Materials Engineering, Chung-ju National Univ. , Chungbuk 380-702, Korea b Korea Academy of Industrial Technology, Shiheung 429-450, Korea c 科学技術庁金属材料技術研究所 　305 つくば市 Jun-Ho Seo, Doo-Myun Lee, Kyeongsoon Park a, Jong-Hoon Kim b Isao A. Nishida c, Chi-Hwan LeeDept. of Metallurgical Engineering, Inha University, Inchon 402-751, Korea a Dept. of Materials Engineering, Chung-ju National Univ. , Chungbuk 380-702, Korea b Korea Academy of Industrial Technology, Shiheung 429-450, Korea c National Research Institute for Metals, Tsukuba 305, Japan  The p-type Bi0.5Sb1.5Te3 compound doped with 4.0 wt% Te was fabricated by the hot extrusion at the temperature range of 300-510 deg.c under an extrusion ratio of 20:1 and a ram speed of 5 cm/min. The microstructure of the compound was investigated by scanning electron microscopy and X-ray diffraction. The microstructure was highly dense and fine-grained (~1.0micrometer). The hot extrusion gave rise to a preferred orientation of grains. With increasing the extrusion temperature, the bending strength and figure of merit were increased due to the porosity decrease. The highest bending strength (92 MPa) and figure of merit (2.94 x10**-3/K) were obtained at 440 deg.c. It is proposed that the hot extrusion reduced a grain size and increased a density, resulting in an improvement in bending strength and figure of merit. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 551-556 単向的Unidirectionallyに凝固したn-Bi2Te3の熱電特性と異方性Anisotropiesに対するドーパントの効果 Effect of Dopants on Thermoelectric Properties and Anisotropies for Unidirectionally Solidified n-Bi2Te3 安倍のぞみ a、桑折仁 b、塩田一路 a、西田勲夫 ca 工学院大学　192 東京都八王子市中野町2665-1 b 東北大学　金属材料研究所　980-77 宮城県仙台市青葉区片平2-1-1 c 科学技術庁 金属材料技術研究所　305 茨城県つくば市千現1-2-1 N.Abe a, H.Kohri b, I.Shiota a, and I.A.Nishida ca Department of Chemical Engineering, Kogakuin University, 2665-1 Nakano-machi, Hachioji-city, Tokyo, 192, Japan b Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai-city, Miyagi, 980-77, Japan c National Research Institute for Metals, 1-2-1 Sengen, Tsukuba-city, Ibaraki, 305, Japan  It is wellknown that thermoelectric properties of n-type Bi2Te3 compounds are affected by dopants. In this work, we used HgBr2, HgI2, SbBr3 and SbI3 as the dopants. As a result, electrical resistivity (rho) of specimens doped with Sb compounds showed a drop of about 18% as compared with Hg compounds. Thermal conductivity (kappa) of specimens doped with bromide showed a drop of about 6% as compared with iodine. The figure of merit Z of specimen doped with SbI3 showed the greatest value of 3 .88x10**-3K**-1 in these specimens.　On the other hands, Bi2Te3 compounds have large anisotropy in the thermoelectric properties because of its crystal asymmetry of R3m. In this work, anisotropies in hall coefficient RH and (rho) of specimens doped with Hg compounds showed about 1.3 times as compared with Sb compounds. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 557-562 アーク融解したシリコンホウ化物の熱電特性 Thermoelectric Properties of Arc-melted Silicon Borides 陳立東、後藤孝、平井敏雄東北大学　金属材料研究所　980-77 宮城県仙台市青葉区片平2-1-1 Lidong Chen, Takashi Goto, Toshio HiraiInstitute for Materials Research, Tohoku University, Katahira 2-1-1 , Aoba-ku, Sendai 980-77, Japan  Silicon borides were prepared by arc melting in a boron content range from 80 to 94mol%. As-melted specimens consisted of SiBn and free silicon. After heat treatment at 1500-1673K, SiB4 formed near the SiBn-Si boundary due to the solid reaction between free silicon and SiBn, and as the result SiBn-SiB4 composites were obtained. The SiBn-SiB4 composites showed larger electrical conductivity and smaller thermal conductivity than the as-melted silicon borides, which leads to an improvement of thermoelectric figure of merit. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 563-568 プラズマ溶射成形法による傾斜熱電材料 Graded thermoelectric materials by plasma spray forming Jurgen Schilz a, Eckhard Muller a, Wolfgang A. Kaysser a, Gregor Langer b Erich Lugscheider b Gunter Schiller c, Rudolf Henne ca German Aerospace Research Establishment (DLR), Institute of Materials Research, D-51140 Koln Germany b Aachen, University of Technology, Materials Science Institute Julicher Str. 342, D-52056 Aachen, Germany c German Aerospace Research Establishment (DLR), Inst. for Technical Thermodynamics, D-70503 Stuttgart, Germany Jurgen Schilz a, Eckhard Muller a, Wolfgang A. Kaysser a, Gregor Langer b Erich Lugscheider b Gunter Schiller c, Rudolf Henne ca German Aerospace Research Establishment (DLR), Institute of Materials Research, D-51140 Koln Germany b Aachen, University of Technology, Materials Science Institute Julicher Str. 342, D-52056 Aachen, Germany c German Aerospace Research Establishment (DLR), Inst. for Technical Thermodynamics, D-70503 Stuttgart, Germany  Plasma spraying is a consolidation process for powders with the additional capability of a composition control of the spray formed structures. The paper reports on the first steps to adapt this method to the production of functionally graded thermoelectric materials with a locally maximized figure of merit. Iron disilicide (FeSi2) was used to test the performance of the technique on thermoelectric material. It was found that plasma spray forming is applicable to produce dense materials with thermoelectric properties comparable to hot pressed ones. Problems were however found with the thermal stability of the microstructure.Final goal is the employment of plasma spraying to form compositionally graded materials of the Mg2(Si,Ge,Sn) system. Here we report on the preparation and thermoelectric transport properties of Si-rich quasibinary Mg2(Si,Ge) and Mg2(Si,Sn) mixed crystals by mechanical alloying. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 569-573 溶製材料の接合によるPbTe-FGMの作製 Preparation of PbTe-FGM by Joining Melt-grown Materials 折橋正樹 a、野田泰稔 b 陳立東 a、康燕生 c、毛呂明夫 c、平井敏雄 aa 東北大学　金属材料研究所　980-77 宮城県仙台市青葉区片平2-1-1 b 東北大学　工学部　980-77 宮城県仙台市青葉区荒巻青葉 c 航空宇宙技術研究所　角田宇宙推進技術研究センター　981-15 宮城県角田市君萱小金沢1 M. Orihashi a, Y. Noda b L. -D. Chen a, Y. -S. Kang c, A. Moro c and T. Hirai aa Institute for Materials Research, Tohoku University, Katahira, 2-1-1, Aoba-ku, Sendai, Miyagi 980-77, Japan b Faculty of Engineering, Tohoku University, Aramaki Aoba, Aoba-ku, Sendai, Miyagi 980-77, Japan c National Aerospace Laboratory, Kakuda Research Center, Koganezawa 1, Kimigaya Kakuda, Miyagi 981-15, Japan  The 2-stage carrier concentration FGM of PbTe were prepared by plasma activated sintering (PAS) using the discs cut from melt-grown PbTe ingots. The component materials of PbTe ingots were prepared by the Bridgman method after the direct melting of the constituent elements (Pb and Te) and 2000 or 4000 molppm PbI2 as a n-type dopant. The PAS conditions were as follows; in vacuum, pressure of 30 MPa, temperature at 1050-1100 K, and current of 600 A and voltage of 25 V. The powder of either of the component materials was adopted as joining reagent of the discs. The thermoelectric characterization of the FGM was made in the temperature range from 300 to 700 K. The electrical conductivity of the FGM at 300 K was almost intermediate between those of the components, while the thermoelectric power corresponded to that of the component with high carrier concentration at high temperature side. The thermoelectric power for the FGM was almost intermediate between those for the components. At T>650 K, the electrical figure of merit for the FGM was larger than that for the components. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 575-580 n型セグメント化 PbTeの熱電特性の改善と熱安定性 Improvement and thermal stability of thermoelectric properties for n-type segmented PbTe 米田征司 a、海部宏昌 a、奥村次徳 a、篠原嘉一 b、今井義雄 b、西田勲夫 b 持丸敏明 c、高橋一寿c、野口照夫 c、塩田一路 da 東京都立大学工学部電子情報工学科　192-03 東京都八王子市南大沢1-1 b 科学技術庁 金属材料技術研究所　305 茨城県つくば市千現1-2-1 c 真空冶金株式会社　289-1297 千葉県山武郡山武町横田516 d 工学院大学　192 東京都八王子市中野町1665-1 S. Yoneda a, H.T.Kaibe a, T. Okumura a, Y. Shinohara b, Y. Imai b, I.A. Nishida b T. Mochimaru c, K. Takahashi c, T. Noguchi c and I. Shiota da Department of Electronics and Information Engineering, Tokyo Metropolitan Universisty, 1-1, Minami-Ohsawa, Hachioji-shi, Tokyo, 192-03, Japan b National Research Institute for Metals, 1-2-1, Sengen, Tsukuba-shi, Ibaraki, 305, Japan c Vacuum Metallurgical Co., Ltd., 516 Yokota, Yamatake-cho, Yamatake-gun, Chiba, 289-12, Japan d Kogakuin University, 2665-1 Nakano-cho, Hachioji-shi, Tokyo, 192, Japan  The resistivities (rho) of the n-type melt-grown and plasma activated sintered PbTe were measured as a function of temperature during heating and cooling cycles to progressively higher temperatures until 903 K in Ar atmosphere. The hysterisis of the temperature dependence of (rho) appeared for both specimens after heated at 703 K, which indicates that the change of thermoelectric properties occurs during the operation as a thermoelectric generator. This phenomena was more remarkable for the sintered specimen than that for the melt-grown one. However, X-ray analyses did not detected the evidence such as the appearance of the secondary phase or oxidation. The each specimen prepared by melt-grown and plasma activated sintering was also annealed in an evacuated quartz tube at 793 K for 8.64x10**4 s (24 h) . (rho) and the carrier concentrations for both specimens were almost unchanged after annealing. Then, it is pointed out that a PbTe thermoelectric generator is required to be used in a closed evacuated container in order to prevent the change of the thermoelectric properties during operation. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 581-586 IrSb3の作製と熱電特性 Preparation and thermoelectric properties of IrSb3 腰越美営 a、塩田一路、篠原嘉一 b、今井義雄 b、西田勲夫 ba 工学院大学　192 東京都八王子市中野町2665-1 b 科学技術庁 金属材料技術研究所　305 茨城県つくば市千現1-2-1 M. Koshigoe a, I. Shiota" , Y. Shinohara b , Y. Imai b , I. A .Nishida ba Department of Chemical Engineering Kogakuin Univ., 2665-1 Nakano-cho , Hachioji-city , Tokyo 192 , Japan b National Research Institute for Metals , 1-2-1 Sengen , Tsukuba-city , Ibaraki 305 , Japan  An attempt is made to fabricate IrSb3 compound and Ir1-xCoxSb3(X=0. 12) solid solution by the liquid-solid phase sintering and hot-pressing techniques. The compound and solid solution were found to be single phase of IrSb3 and Ir0.88Co0.12Sb3 by X-ray diffractometry, respectively. The electrical resistivity and Hall coefficient were measured in the temperature range from 80K to room temperature. The hot-pressed IrSb3 and Ir0.88Co0.12Sb3 were p-type degenerated semiconductors with hole concentration of 9.53 and 6.80x10*24/m**3 ,respectively. The cobalt atoms act as donors in the solid solution. The hole mobilities for both of the hot-pressed materials (IrSb3 and Ir0.88Co0.12Sb3) were larger than for the liquid-solid phase sintered and hot-pressed materials. A high thermal stability was obtained in hot-pressed IrSb3. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 587-592 溶製PbTeおよびPbTe焼結体のプラズマ活性焼結によるp-n接合 p-n Joining of Melt-Grown and Sintered PbTe by Plasma Activated Sintering 康燕生 a、野田泰稔 b、陳立東 c、木皿且人 a、新野正之 aa 航空宇宙技術研究所　角田宇宙推進技術研究センター　981-15 宮城県角田市君萱小金沢1 　b 東北大学　工学部　980-77 宮城県仙台市青葉区荒巻青葉 　 c 東北大学　金属材料研究所　980-77 宮城県仙台市青葉区片平2-1-1 Y.-S. Kang　a, Y. Noda b, L. -D. Chen c, K Kisara a and M. Niino aa National Aerospace Laboratory, Kakuda Research Center, Koganezawa 1, Kimigaya, Kakuda-City, Miyagi 981-15, Japan. b Faculty of Engineering, Tohoku University, Aoba-Aramaki, Aoba-ku, Sendai, Miyagi 980-77, Japan. c Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai, Miyagi 980-77, Japan  A p-n junction of PbTe thermoelectric material was prepared by plasma-activated sintering (PAS) in order to investigate the junction interface of a stepwise carrier concentration FGM. The component materials were undoped p-type and 2000 or 4000 molppm PbI2-doped n-type, respectively. The n-type component was made from a mixture of PbTe and PbI2 powder or a powder which was obtained by grinding a PbI2 doped melt-growth crystal. The microscopic observation was carried out for the component materials, which indicated the grain growth during PAS. The electric properties were almost consistent with those for the single crystals. The characterization of the p-n junction was carried out by measuring thermoelectromotive force, voltage profile and current(I)-voltage(V) relationship across the joint boundary. An abrupt change of conduction type for the thermoelectromotive force and a continuous distribution for the voltage were observed at the joint boundary. The voltage profile was different from that of the stepwise FGMs of SiGe and PbTe with abrupt change at the joint boundary. The I-V relationship in forward and reverse direction bias differs each other which was limited in low voltage region. These results indicate that the junction was successfully performed by the PAS process. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 593-598 傾斜機能Si-Ge熱電材料の試作 Trial Manufacture of Functionally Graded Si-Ge Thermoelectric Material 野口照夫、高橋一寿、増田忠真空冶金株式会社　289-12 千葉県山武郡山武町横田516 T. Noguchi, K. Takahashi, and T. MasudaVacuum Metallurgical Co., Ltd. 516 Yokota, Sambu-machi, Sambu-gun, Chiba-ken, 289-12 Japan  A functionally graded material of SiGe was manufactured by using spark-plasma-sintering (SPS) in a trial. The studied material was mainly a p-type 80Si-20Ge alloy in which doping concentration of B were graded stepwise in three levels of 0.027, 0.2, and 0.58 at %. Preliminary evaluation was made for the manufactured material samples in terms of their Seebeck coefficients together with electrical resistivities. Measurement of resistivity distribution around the FGM boundary was carried out to localize the boundary.      SUMMARY AND CONCLUSION      A functionally graded material of SiGe was manufactured by using spark-plasma-sintering (SPS) process in a trial. The studied material was mainly an 80Si-20Ge alloy in which doping concentrations of B were graded stepwise in three levels of 0.027, 0.2, and 0.58 at%.    Some preliminary evaluation was made for the manufactured material samples in terms of their Seebeck coefficients as well as electrical resistivities. Thermoelectric properties were unsatisfactory so far because of no optimization in material design such as doping content, dimensions, and geometrical structures. The boundary layer between the graded doping was investigated in the manner of electrical resistivity measurement. It was suggested that diffusion of dopant occurred during sintering and resulted in a broad boundary layer as wide as 3-4mm. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 599-604 (Si-MoSi2)/SiGe熱電変換素子ユニットの微細構造と特性 Microstructure and property of (Si-MoSi2)/SiGe thermoelectric convertor unit 林君山 a、谷畑公昭 a、宮本欽生 a、木戸博康 ba 大阪大学産業科学研究所　567 大阪府茨木市 b 大阪市立工業研究所　536 大阪市城東区森之宮 J. S. Lin a, K. Tanihataa, Y. Miyamoto a and H. Kido ba The Institute of Scientific & Industrial Research, Osaka University, Ibaraki 567, Osaka, Japan b Osaka Municipal Technical Research Institute, Morinomiya, Jhoto-Ku 536, Osaka, Japan  This research suggested a one-step process to fabricate the thermoelectric conversion cell with its electrode. Si0.78Ge0.22 alloy and (Si-MoSi2) composite were used as a thermoelectric conversion material and an electrode material, respectively. The HIP process was employed to prepare samples. The experimental and theoretical analyses on the thermal stress and electrical resistivity identified that this process has good prospects to substitute for jointing of SiGe with electrode . English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 605-610 多孔率制御が行われたSiC/B4C+PSS熱電特性の温度依存 Temperature Dependence of the Porosity Controlled SiC/B4C+PSS Thermoelectric Properties 加藤和彦、有賀敦、岡本庸一、守本純、宮川浹防衛大学校　材料物性工学239 神奈川県横須賀市走水1-10-20 K. Kato, A. Aruga, Y. Okamoto, J. Morimoto and T. MiyakawaDepartment of Materials Science and Engineering, National Defense Academy, 1 -10-20, Hashirimizu, Yokosuka, Kanagawa, Japan, 239  In the previous paper, it was reported that the thermoelectric properties of SiC/B4C system could be controlled by the addition of PSS at room temperature. In this report, the porous structure of these samples were confirmed by using SEM, and the measurements were carried out on the temperature dependence of the thermoelectric properties from room temperature up to 600 deg.C (the thermal conductivity up to 300 deg.C ). The figure of merit of the sample (B4C: 2.0 wt.% + PSS: 5.0 wt. %) is estimated about 2 x10**-6 K**-1 around 600 deg.C. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 611-616 PSSの添加によるB4C-B系複合材料の製造およびその熱電特性 Preparation of B4C-B System Composites adding PSS and their Thermoelectric Properties 有賀敦、K. Tsuneyoshi、岡本庸一、守本純防衛大学校 材料物性工学239 神奈川県横須賀市走水1-10-20 A. Aruga, K. Tsuneyoshi, Y. Okamoto and J. MorimotoDepartment of Materials Science and Engineering, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239, Japan  B4C-B quasi-binary composites were prepared at 1950 deg.C, 2100 deg.C and 2250 deg.C by pressureless sintering in argon atmosphere using commercially manufactured B4C and amorphous B powders adding 0.5 wt.% polysilastyrene (PSS). AsB9C possesses higher thermoelectric property as p-type semiconductors applied at high temperature, in this study we focused upon the lattice constant, density, electric resistivity, thermal conductivity, and Seebeck coefficient.  Carbon concentration added on preparation over range 7 - 20 at. % at room temperature were addressed. Also figure of merit (Z) of specimens were calculated.X-ray powder diffraction (XRD) revealed that the phase of specimens were mainly B12(C, Si, B)3 and a little carbon. Si was detected by energy disparsion X-ray spectrometer (EDX), but SiC did not appear on XRD, though Si and C elements were due to a pyrolysis of PSS. Namely, isostructure substitution occurred at a site of C in B4C. Sintering density is less than 70 % that of B4C, especially lower in the range of 7-9 at.% C owing to excess B. SEM observation showed a lot of opening pores , but particles were binded and grain growth occurred at higher temperature. The values of thermal diffusivity were from 3 to 13 m**2/s. Specific heat of samples was almost all 1.0 J/gK. Then thermal conductivities of these composites were at a range of 4-23 W/mK. Electric resistivity (7x10**-3 ~ 6x10**-2 (ohm)m) tended to increase with increasing C content, while Seebeck coefficient (0.30-0.38 mV/K) showed opposite tendency. Consequently, the largest Z value of these B4C-B composites was about 2.4x10**-6 K**-1 at room temperature.  English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 617-622 異なるキャリア濃度のn型PbTeの接合およびその熱電特性 Joint of n-type PbTe with Different Carrier Concentration and its Thermoelectric Properties 今井義雄、篠原嘉一、西田勲夫、岡本昌明、磯田幸宏、T.Ohkoshi、T.Fujii、塩田一路 a、海部宏昌 b金属材料技術研究所　305 茨城県つくば市千現1-2-1 a 工学院大学　192 東京都 b 東京都立大学　192-03 東京都 Y.Imai, Y.Shinohara, I.A.Nishida, M.Okamoto, Y.Isoda, T.Ohkoshi, T.Fujii, I.Shiota a and H. T . Kaib ebNational Research Institute for Metals, STA, Ibaraki 3 05, Japan  a Kogakuin University, Tokyo 192, Japan b Tokyo Metropolitan University, Tokyo 192-03, Japan  The experimental examination and investigation have been carried out on the jointed n-type PbTe ingot and the sintered n-type PbTe compact with 3 layers of graded electron concentrations nes to develope a higher efficient thermoelectric material. The jointed ingot composed of materials with ne=0.18 and 4.5x10**25/m**3 was prerared by diffusion jointing apparatus. No jointing boundary was confirmed by the opitical microstructure observation. Both the electrical resistivity (rho)and Seebeck coefficient (alpha) of the jointed ingot were strongly affected by the lower part of ne=0.18x10**25/m**3 at lower temperature and by the higher part of ne=4.5x10**25/m**3 at higher temperature. The sintered compact with 3 layers of ne=3.51, 2.60 and 2.26x10**25/m**3 was prepared by the hot-pressing technique. It was found that the graded structure of ne. can perform a 7% higher effective maximum power than the homogeneous structure at a temperature difference of 280K. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 623-626 Si80Ge20焼結合金の熱電特性に対してプラズマ処理が与える影響 Effects of plasma treatment on thermoelectric properties of Si80Ge20 sintered alloys 岸本堅剛 a、長本泰征 a、小柳剛 a、松原覚衛 ba 山口大学 電気電子工学科　755 宇部市常盤台2557  b 山口東京理科大学 電子基礎工学科　756 小野田市大学通1-1-1 K. Kishimoto　a, Y. Nagamoto　a, T. Koyanagia, and K. Matsubara　ba　Department of Electrical and Electronic Engineering, Yamaguchi University, 2557, Tokiwadai, Ube 755, Japan. b　Department of Electronics and Computer Science,Science University of Tokyo in Yamaguchi, 1- 1-1, Daigakudori, Onoda 756, Japan.  A microstructure control at grain boundaries of SiGe sintered alloys has been attempted to improve their thermoelectric figure-of-merit. SiGe raw micrograins were exposed to GeH4-plasmas to be coated with Ge layers, and then were sintered. Results of the microstructure analysis suggested that the plasma-treated alloys had Ge-rich layers around grain boundaries. In these alloys, a reduction of the thermal conductivity and increases in the electrical conductivity and the Seebeck coefficient were observed. This favorable change of the thermoelectric properties may be associated with the microstructure modification around grain boundaries. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 627-632 FGMアプローチによるマンガンケイ化物の熱電特性の温度依存の制御 Control of Temperature Dependence of Thermoelectric Properties of Manganese Silicide by FGM Approach 梶川武信、Seiya Suzuki、志田啓亮、Sunao Sugihara湘南工科大学　251 神奈川県藤沢市 Takenobu Kajikawa , Seiya Suzuki , Keisuke Shida , and Sunao SugiharaShonan Institute of Technology Fujisawa, Kanagawa 251 JAPAN  The manganese silicide is one of interesting materials for power generation application utilizing high temperature resources. In the paper the temperature dependence of thermoelectric properties is described for the sintered manganese silicide with two kinds of dopant concentrations from 350K up to 1100K. In the experiments the characteristic of the temperature dependence is possibly controlled by the combination of carrier concentration with macro-structure aiming a broad temperature dependence of the figure of merit by FGM approach. The experimental results suggest that the combined control of two kinds of parameters is effective to get a good FGM thermoelectric element due to the sintered manganese silicide for a broad temperature range from 350 to 1100K. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 633-638 絶縁された金属シート上の熱電フィルムによる感熱装置 Heat Sensing Device with Thermoelectric Film Laid on Insulated Metal Sheet 天野隆、神谷直樹、鴇田滋樹株式会社 イムラ材料開発研究所　448 愛知県刈谷市八軒町5-50 T. Amano, N. Kamiya and S. TokitaIMRA MATERIAL R&D CO., LTD. 5-50, Hachiken-cho, Kariya city, Aichi pref., 448, Japan  We investigated a thermoelectric thermal sensor which responded to heat in a short time and generated electricity to drive electric parts such as a light emitting diode or a piezoelectric buzzer. The sensor was composed of the insulated metal sheet and thermoelectric thick films on it. The device contained 8 pairs of iron disilicide thermocouple connected in series, generated 1.5 V within 5 seconds and 2.8 V within 25 seconds reacting to a gas flame. The compositions of the thermoelectric iron disilicide thick films were Fe0.92Si2.5Mn0.08 for p-type and Fe0.98Si2.5Co0.02 for n-type, respectively. The iron disilicide thick films are melted to reduce their porosity for good heat resisting property. Their peeling sensibility and residual stress were also reduced by melting. Adding Si in the film more than stoichiometric composition of the iron disilicide promoted recrystallization to a semiconducting beta-FeSi2 phase and improved thermoelectric property of the film. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 639-646 酸化熱電子変換素子の最近の開発 Recent Developments in Oxygenated Thermionic Converters J.-L. DesplatRasor Assoc. Inc., 5670 Stewart Ave., Fremont, CA 94358, USA J.-L. DesplatRasor Assoc. Inc., 5670 Stewart Ave., Fremont, CA 94358, USA  Addition and control of oxygen in thermionic converters is the key to achieving high efficiencies and power densities. Converters with collectors containing cesium oxide, and with cesium oxide vapor circulation have shown barrier indices near 1.9eV. A new method, based on sputtering and readsorption for measuring the vapor pressures of both cesium and oxygen-bearing species in research converters was developed. In addition, the vapor phase in research devices operating under similar conditions was sampled by time-of-flight mass spectrometry: vapor pressures of Cs2O around 1x10**-7 Torr were detected in Cs pressures around 1 Torr. These Cs2O pressures were consistent with those obtained using the readsorption technique.       English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 647-654 耐火金属酸化物コレクター材料の開発およびその熱電子変換素子の性能 Development of Refractory Metal Oxide Collector Materials and Their Thermionic Converter Performance 福田隆三、春日康弘、加藤 健電子技術総合研究所 エネルギー部　305 茨城県つくば市梅園 R.Fukuda, Y.Kasuga and K.KatohEnergy Division, Electrotechnical Laboratory, Umezono, Tsukuba-shi, Ibaraki 305 Japan  Refactory metal oxides of NbOx, WOx, TaOx, and Silver oxide (AgOx) have been studied for a high performance collector. The metal oxide materials were deposited on metal substrates by RF sputtering in the Ar/O2 gas mixture, in which the partial pressure of O2 was deliberately set at the lower values in order to sputter in the stoichiometrically oxygen gas short conditions. Work function of the metal oxides was measured by cesium plasma immersion technique. As results, minimum work function values of each oxide materials were obtained as follows; AgOx =1.25eV, NbOx =1.38eV, WOx =1.42eV, TaOx =1.43eV. NbOx and AgOx are considered most promising for a collector.    A thermionic converter with a plane parallel type of a polycrystalline W emitter and an AgOx collector, an interelectrode spacing at room temperature 0.1mm, was set up and the power generation experiments were conducted. The maximum power, 3.9W/cm2, 0.6V, 6.5A/cm2, was obtained under the unignited mode operation at TE =1583K. The barrier index was VB =1.5V at T E =1578K. Based on the experimental results, a new type of a FGM collector was proposed for a micro-gap thermionic converter. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 655-660 (0001) 配向レニウム層および傾斜構造のあるエミッターの熱電子特性および熱安定性 Thermionic Properties and Thermal Stability of Emitter with a (0001) Oriented Rhenium Layer and Graded Structure 加藤昌宏 a、福田隆三 b、五十嵐廉 aa 東京タングステン株式会社　931 富山県富山市多岩瀬古志町2 b 電子技術総合研究所　305 茨城県つくば市梅園1-1-4 M. Katoh a, R . Fukuda b and T. Igarashi  aa Tokyo Tungsten Co. , Ltd. , 2 Iwasekoshi-machi, Toyama-shi, Toyama 931 , Japanb Electrotechnical Laboratory, 1- 1-4 Umezono, Tsukuba-shi, Ibaraki 305, Japan  Rhenium exhibits excellent thermionic electron emission characteristics in a cesium plasma converter. Chemical-vapor-deposited rhenium with a preferred (0001) orientation should have advantages over polycrystalline rhenium with respect to thermionic emission. Rhenium layers with (0001)-oriented three-dimensional surfaces have been successfully deposited on molybdenum substrates. The work function of rhenium emitters was estimated to be 4.9 eV from the results of power generation tests. The maximum power of a thermionic energy converter incorporating a rhenium emitter is 2.0 W/cm2 when the temperature of the emitter is 1 800 K, that of the molybdenum collector is 990 K and that of the cesium reservoir is 561 K. The composition and surface morphology of the rhenium layer may change as molybdenum from the substrate diffuses into the rhenium layer at high operating temperatures. In order to improve the thermal stability of the rhenium layers at elevated temperatures, tungsten layers were inserted between the rhenium layers and the molybdenum substrates to form graded composition interfaces. The tungsten layers prevented excessive diffusion of molybdenum into the rhenium layers. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 661-666 効率的な熱電子変換素子の開発 Development of Efficient Thermionic Energy Converter 加藤寿仁 a、森本清水 a、礒貝和博 a、加藤昌宏 b、福島孟 c、福田隆三 da 三井造船エンジニアリング　290 千葉県市原市 b 東京タングステン株式会社　931 富山県富山市c 金属材料技術研究所　305 茨城県つくば市d 電子技術総合研究所　305 茨城県つくば市 T.Kato a, K.Morimoto a, K.Isogai a, M.Kato b, T.Fukushima c, R.Fukuda da Mitsui Engineering & Shipbuilding Co.,Ltd., Ichihara-shi, Chiba 290, Japan b Tokyo Tungsten Co.,Ltd., Toyama-shi, Toyama 931, Japan c National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan d Electrotechnical Laboratory, Tsukuba-shi, Ibaraki 305, Japan  In the near future, thermionic energy converter will be a more promising device for space power generation. To this end, a solar heated thermionic energy converter has been developed by applying functionally graded materials (FGM) to the electrode. It is majorly composed of a W/Re-FGM emitter, a NbOx collector, and a TiC/Mo-FGM solar receiver. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 667-672 原子力電池90Srの熱源に傾斜構造を使用したことによる放射線量の低減 Radiation dose reduction by graded structures in the heat source of a 90Sr radioisotope battery 大橋厚人、植木紘太郎、千田哲也船舶技術研究所　181　東京都三鷹市新川6-38-1 A. Ohashi, K. Ueki and T. SendaShip Research Institute, MOT, 6-38- 1, Shinkawa, Mitaka, Tokyo 181, Japan  We studied possibility of absorbed dose reduction for a cylindrical hollow heat source model of a 90Sr radioisotope battery by adding graded structure. The simulated result for addition of three mixed layers conserving total materials showed 22 % reduction to the dose of non-FGM structure. For compensation of a dose limitation of unmanned mission in SP-100 project, tungsten shield was needed about 5.7 cm thickness with the graded structure which indicated the minimum dose. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 673-679 キセノンが少ないアークランプの照射による熱電子エネルギー変換素子thermionic energy converterの出力の向上 Output increase of thermionic energy converter due to the illumination of Xenon short arc lamp Y.Shibahara、神藤正士静岡大学 電気・電子工学科　432　静岡県浜松市城北3-5-1 Y.Shibahara and M.KandoDepartment of Electrical and Electronic Engineering, Shizuoka University, Johoku 3-5-1, Hamamatsu 432,Japan  The influence of illumination of Xenon short arc lamp radiation on the thermionic energy converter output has been investigated. Here, the thermionic energy converter used in the experiment is designed to keep the space between both electrodes enough widely for the efficient illumination. Through the open end of the cylindrical collector, the light from the Xenon lamp with the nominal output power of 3kW at the maximum illuminates the emitter after being focused by lenses. The cesium gas temperature Tg can be controlled up to 450 K. The weak magnetic field with cusp geometry is applied to guide the electrons to the collector. The main results obtained by the experiment are summarized as follows: 1) The output current operated by the unignited mode increases by 10-50 times due to the illumination for the emitter temperature TE less than 900 K and Tg from 300 to 450 K. But the difference of the output currents with and without illumination decreases as TE increases. 2) The ignited mode appears when Tg is higher than 400 K and the collector is positively biased with respect to the emitter. But, the bias collector voltage for the ignited mode operation largely decreases by the illumination. Especially, the ignited mode operation can be accomplished at TE around 1300 K by the illumination, even if the collector voltage is lower than the emitter voltage. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 681-685 FGM構造コレクタを持つ熱電子変換素子のハイブリッド・モードのコンセプト Hybrid Mode Concept of a Thermionic Converter with a FGM Structured Collector 岩瀬 満雄、平井慶彦東海大学 電気工学科　259-12　 神奈川県平塚市北金目1117 Mitsuo Iwase   Yoshihiko HiraiDepartment of Electrical Engineering, Tokai University Kitakaname 1117, Hiratsuka-shi, Kanagawa 259-12, Japan  A new hybrid mode concept of the thermionic energy converter was proposed. A number of papers dealing with the hybrid mode have been published, but they mainly deal with the mechanism of the arc at the emitter. On the contrary, we proposed, in this study, a new hybrid mode model of the thermionic energy converter with a FGM structured collector. Based on the model, we have experimented to deposit graded linearly molybdenum (Mo) and niobium (Nb) on the substrate considered as the collector.   The results can be summarized as follows:      1. "The ball of fire" yielded on the collector is available for the hybrid mode.      2. This is not to say that the model realize usually. However, FGM technology makes it possible to realize the hybrid mode easily.      3. In the present experiment, Ion Beam Sputtering system was used, in which we designed unsymmetrical target for the FGM technology.      4. The existence of Mo on the substrate was recognized by the XPS peaks, at 227.7 eV for 3 d5/2 and 230.9 eV for 3 d3/2, and for, Nb at 202.7 eV for 3 d5/2 and 205.4 eV for 3 d3/2.      5. Results of XPS for the samples versus distance showed concentration gradients of -0.6 %/cm for Mo and +0.6 %/cm for Nb. Thus, we have obtained a FGM collector, whose cesiated effective work function can be predicted by the SIMCON code.  English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 687-693 電磁砲システムへ応用する熱電変調/ナノスケール多層傾斜材料 THERMOELECTRICALLY MODULATED/NANOSCALE MULTILAYERED GRADIENT MATERIALS FOR APPLICATION IN THE ELECTROMAGNETIC GUN SYSTEMS M.A.OTOONI a、John F. ATKINSON b、I.G.BROWN ca US Army Armament Research, Development and Engineering Center Picatinny Arsenal, N.J. b USA Science and Technology Center, Far-Eastc Lawrence Berkeley Laboratory, University of California, Berkeley, CA M.A.OTOONI a, John F. ATKINSON b and I.G.BROWN ca US Army Armament Research, Development and Engineering Center Picatinny Arsenal, N.J. b USA Science and Technology Center, Far-Eastc Lawrence Berkeley Laboratory, University of California, Berkeley, CA  Analysis of fired rails from electromagnetic railguns indicates severe surface damage occurs due to high current arcing and tribological mismatch. We have explored the behavior of several nanoscale multilayered materials as possible routes to improve the thermomechanical properties of the rail and armature materials. Structures investigated include (i) Ti-Co alloy on Ta-Cu alloy on dlc (diamond-like carbon) on stainless steel; (ii) Ti-Co alloy on Ta-Cu alloy on dlc on Cu, (iii) Ti-Co alloy on Ta-Cu on Cu; and (iv) Ti-Co on Ta-Cu alloy on Al. The alloys were all 50:50 at% and film thicknesses were in the range 400-1000A. The films were formed using a repetitively pulsed vacuum arc plasma deposition method with substrate biasing- and IBAD-like techniques. The surfaces were characterized by scanning electron microscopy, transmission electron microscopy, Rutherford backscattering spectroscopy, optical microscopy, microhardness measurements, arc erosion resistance and scratch resistance tests. Preliminary results show improvement in the microhardness, arc erosion resistance and scratch resistance, most especially for the dlc-coated surfaces. This kind of multilayered approach to the fabrication of electromagnetic railgun and armature surfaces could be important for future advanced Electromagnetic EM Gun systems. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 695-700 微小重力状態および通常重力状態下における傾斜凝固によるＩｎ－Ｓｂ合金の合成 Synthesis of In - Sb alloys by directional solidification in microgravity and normal gravity condition Hideki MINAGAWA, Yoshikazu SUZUKI, Katsuyoshi SHIMOKAWA, Yoshinobu UEDA, Jiro NAGAO, and Junichi KAWABATA北海道工業技術研究所　062　札幌市 Hideki MINAGAWA, Yoshikazu SUZUKI, Katsuyoshi SHIMOKAWA, Yoshinobu UEDA, Jiro NAGAO, and Junichi KAWABATAMaterials Division, Hokkaido National Industrial Research Institute, Agency of Industry and Science Technology, Ministry of International Trade and Industry. Sapporo 062, JAPAN,  Buoyancy convection and gravitational segregation caused by density differences can be suppressed under microgravity conditions. Therefore, it is expected that high quality materials unobtainable on the ground can be produced by homogeneous mixing materials with different densities. On the other hand, compositional gradient which had once formed under normal gravity condition is maintained under microgravity condition. This compositional gradient will be available for the production of functionally graded material. In this study, as a fundamental research for production of functionally graded material, the synthesis of indium antimonide with several compositional ratio has been carried out under a short time microgravity conditions. Microgravity experiment has been performed by 1 .2 sec drop tower facility in Hokkaido National Research Institute ( HNIRI ). The structure of indium antimonide alloy concerning with composition has been investigated. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 701-706 傾斜組成を伴うフルカラー亜鉛没食子酸塩蛍光体 Full-colored Zinc Gallate Phosphor with Graded Composition 遠藤忠, Kyota Uheda and Hirotsugu Takizawa東北大学　工学部　分子化学工学科980-77　宮城県仙台市青葉区青葉 Tadashi Endo, Kyota Uheda and Hirotsugu TakizawaDepartment of Molecular Chemistry and Engineering, Faculty of Engineering, Tohoku University, Aoba, Aoba-ku, Sendai, Miyagi 980-77, JAPAN  (Zn1-xMx)Ga2O4 (M=Cd2+, Mn2+) and Zn(Ga1-xMx)2O4(M=Al3+ , Cr3+) were prepared under the conditions of 1000deg.C to1400deg.C for 3 to 24 h in air and flowing nitrogen or argon gas. The solid solutions were identified as a single phase with spinel structure. On doping Al3+ and Cd2+ ions, absorption edges were continuously changed with the concentration of dopant. In particular, the self-activated emission peak sifted to the positions in the range of 450nm to 570nm with increasing the x of (Zn1-xCdx)Ga2O4. The doped Mn2+ and Cr3+ ions functioned only as color centers, corresponding to the 3d-3d transitions . As a result, it was found that the intense emissions of ZnGa2O4 substitutes were essentially induced by the donor-acceptor recombination due to the graded and non-stoichiometric compositions. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 707-712 モデルCuO/Sn0O2酸素センサーの合成と特性評価 Synthesis and characterization of a model CuO/SnO2 Oxygen sensor Preben. J. Moller, Zheshen Li and Qinlin GuoDepartment of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark Preben. J. Moller, Zheshen Li and Qinlin GuoDepartment of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark  Tin dioxide (SnO2) is an insulator in its stoichiometric form, but in practice the nonstoichiometric form is always encountered and behaves as a semiconductor due to the presence of defects or deliberate doping. It is a very promising material for gas sensor application because of its very good chemical stability and good surface conductivity.       There are many works on polycrystalline SnO2, and it has achieved great success in gas sensor applications. But only a few works have been carried out on single crystals. This may be because of the difficulty of growing large and perfect crystals.       In this paper, we will discuss the structural and electronic properties of interfaces formed by Cu deposits on the (110) and the (101) surfaces of SnO2, and the subsequent formation of a CuO overlayer by oxidation. Due to the lattice mismatch, epitaxial growth of CuO on the SnO2 single crystal is not expected. We will therefore deposit nanoscale small particles of Cu in small steps, and oxidize these at each step to CuO, gradually increasing the size of the particles of this material in order to obtain a stronger bonding to the SnO2 surface. With this in mind, we have studied two low-index SnO2 surfaces in order to see the influence of SnO2 crystal structure in the interfacial region on sensor properties. To understand the micro-properties of that structure used as an oxygen sensor, the changes in electrical conductivity of the ultrathin sandwich-layer system was at the same time followod in situ through measurements of the changes of the current passing through this n-type (SnO2 substrate) and p-type (the fully oxidized CuO overlayer) heterojunction system as a function of oxygen exposure, thus enabling us to characterize and optimize its behaviour as an oxygen sensor (and actuator) . English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 713-718 マルテンサイト変換法による磁気傾斜機能材料の製造 Fabrication of Magnetic Functionally Graded Material by Martensitic Transformation Technique 渡辺義見 a, 中村祐三 b , 福井泰好 ba.信州大学　Department of Functional Machinery and Mechanics　386　上田市b.鹿児島大学　Department of Mechanical Engineering　890　鹿児島市 Yoshimi Watanabe a, Yuzo Nakamura b and Yasuyoshi Fukui ba.Department of Functional Machinery and Mechanics, Shinshu University, Ueda 386, Japan b.Department of Mechanical Engineering, Kagoshima University, Kagoshima 890, Japan  It is known that the paramagnetic phase in an austenitic stainless steel, such as Fe-18Cr-8Ni, transforms into a ferromagnetic (alpha)'-martensite phase by plastic deformation at low temperature. The amount of saturation magnetization due to the martensitic transformation increases with increasing plastic strain. Thus, a manufacture of magnetically graded materials based on the concept may require the inhomogeneity of plastic deformation. In the present study, it is aimed to obtain a suitable gradient of the magnetization by introducing inhomogeneous deformation and to examine the relationship between the magnetization and applied plastic strain using Fe-18Cr-8Ni. A simple model to evaluate the distributions of strain and saturation magnetization is obtained in order to clarify the results mentioned here. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 719-723 イオンビーム解析を用いた単結晶性Cu/Nb多層性フィルムの特性評価 Characterization of single-crystalline Cu/Nb multilayer films by ion beam analysis S. Yamamoto, H. Naramoto, B. Tsuchiya and Y. Aoki日本原子力研究所　370-12　群馬県高崎市綿貫町1223 S. Yamamoto, H. Naramoto, B. Tsuchiya and Y. AokiDept. of Materials Development, Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma, 370-12 Japan  Successful growth of Cu/Nb single crystal multilayer films on sapphire substrates with different orientations is reported based on the crystal symmetry characterization using the planar channeling technique. The difference in lattice structure and the big lattice mismatching was overcome by adjusting the substrate temperatures. The layered structure was prepared by using electron-beam evaporation under UHV condition. The typical thicknesses of Cu and Nb layers were in the range of 50 nm to 250 nm. The exact orientation relationship among Cu, Nb layers and sapphire substrate was determined through the mapping of planar channeled points at each layer of Nb, Cu and sapphire. The growth habit depends on the substrate orientations: Nb(110)/Cu(111)/Nb(110) on sapphire (1120) and Nb (100)/Cu (100)/Nb (100) on sapphire (0112) . English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 725-730 赤外線レーザー照射による28Siの濃縮 Enrichment of 28Si by Infrared Laser Irradiation T.Tanaka、塩田一路、 H.Suzuki、T. Noda工学院大学　192　東京都八王子市中野町2665-1National Research Institute for Metals, 1-2-1, Sengen, Tsukuba, Ibaraki 305, Japan T.Tanaka, I.Shiota, H.Suzuki, and T.NodaKogakuin University, 2665-1, Nakano-cho, Hachioji, Tokyo 192, Japan National Research Institute for Metals, 1-2-1, Sengen, Tsukuba, Ibaraki 305, Japan  The enrichment of 28Si has been studied using isotope selective decomposition of Si2F6 by infrared pulse laser. 28Si was enriched in the residual Si2F6 by the laser irradiation at 952-956 cm-1 where Si2F6 containing 29Si and 30Si preferentially decomposed to SiF4. The 28Si content increases with lowering the flow rate of Si2F6 and increasing the laser power. Especially the addition of inert gases such as He and Ar to the source gas accelerates the enrichment of 28Si. Under the optimum condition, Si2F6 gas with a maximum 28Si content of 99.72% could be continuously produced. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 731-736 竹の適応的機能傾斜構造 Adaptive and Functionally Graded Structure of Bamboo 天田重庚、清水尚之群馬大学　376　群馬県桐生市天神町1-5-1Mitsuba Electric Co. Ltd. 1-2681, Hirosawa, Kiryu, Gunma, Japan 376 Shigeyasu Amada* and Naoyuki Shimizu**Department of Mechanical Engineering, Gunma University, 1-5-1, Tenjin, Kiryu, Gunma, Japan 376 Mitsuba Electric Co. Ltd. 1-2681, Hirosawa, Kiryu, Gunma, Japan 376  Bamboo is a natural composite material reinforced by fibers called bundle sheaths, and also a functionally graded and hierarchical structural material. Bamboo grown on the slanted ground cannot grow straight up because it is subjected to a large bending moment due to its own weight. To avoid such a state, it will be bent toward the gravitational direction. This bent part must be reinforced in some way to support the upper portion of the bamboo, for example reinforced by reaction wood for the most of trees. This paper presents how bamboo reacts to such loading conditions. Typically, the cross-section of the bamboo culm changes from circular to elliptical shape which leads to a reduction of the stress generated by the bending moment. It is concluded that the shape of the reaction wood for bamboo is closely related to the loaded bending moment. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 737-742 天然複合材料のインテリジェントモデリングシステムから得られる傾斜機能材料のデザインに関する学習点 Learning about design of FGMs from intelligent modelling system in natural composites 野方文雄姫路工業大学工学部機会工学科　671-22　姫路市 Fumio NogataHimeji Institute of Technology, Dept. of Mechanical Engineering, Himeji,671-22,Japan  It was found that plants have a cell-based sensing system for external mechanical stimuli, which is similar to the role of piezoelectric effects in bone, i.e., mechanical stress will change the resting electrical potential of plants therefore influencing the growth activity of their load carriers. The shape and ingenious construction observed in natural composites are a continuos process of the intelligent optimization based on the adaptive modeling with a cell-based mechanosensor. It seems that this process is the best choice to survive in hard competition for energy and external mechanical condition with minimum materials that they get in the limited living space. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 743-748 機能傾斜木材を用いた防火ドアの開発 Development of the fire door with functionally graded wood 月東秀夫、石原茂久アイカ工業株式会社　R&D Division　490-11　愛知県海部郡甚目寺町大字上萱津字深見24京都大学　木質科学研究所　611　京都府宇治市五ヶ庄 H.Getto and S.IshiharaR&D Division, Aica Kogyo Co.,Ltd., Japan 24, Fukami, Kamikayazu, Jimokuji- cho, Ama- gun, Aichi, 490-11, Japan  Wood Research Institute, Kyoto University, Japan Gokasho, Uji- shi, Kyoto, 611, Japan  Inflammable materials like a wood can be use for the fife door by the Ministry of Construction Notice No.1125 in 1990. Wood has good fire endurance when it was made with a large thickness dimension. A door, however, cannot be made with such a large thickness dimension for building purpose, especially in thin panel-stile constructed doors flames the thin panels on fire.       In order to improve this behavior, fire retardant wood treated with phosphorus and nitrogen compounds was tested for use in fire doors. Here two treatment methods are compared, which are heat- dried treatment and heat- pressed one. It was recognized that the latter method is more useful than the former method, because density of wood and concentration of chemicals are raised at the surface by the former method and they decrease gradually from the surface to the center.      In this system it was recognized that gradient of fire resistance with chemical reactions such as phosphorylation, esterification and polymerization among chemicals and wood occurred on its surface in presence of water.       Then laminated boards with surface layers treated this way were used for panels of a wooden fire door and it has been authorized by the Ministry of Construction. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 749-754 生体適合性テストにおける機能傾斜歯科移植組織の要素マッピング Elemental mapping of functionally graded dental implant in biocompatibility test 亘理文夫、横山敦郎、佐相史徳、宇尾基弘、大川昭治、川崎貴生北海道大学歯学部　060　札幌市 Fumio WATARI, Atsuro YOKOYAMA Fuminori SASO, Motohiro UO, Shoji OHKAWA, and Takao KAWASAKISchool of Dentistry, Hokkaido University, Sapporo 060, JAPAN  INTRODUCTION      The dental implant composed of biocompatible metal, Ti and ceramics, hydroxyapatite(HAP), with the structure of functionally graded materials(FGM) has been fabricated to satisfy both mechanical properties and biocompatibility[1,2]. The miniature FGM implant was made and implanted in the femora of rats to evaluate biocompatibility [3]. The tissue including the implant was sliced to thin section and each section was observed by optical microscopy after staining [1] . In animal test biocompatibilty is evaluated from histological observation to check the inflammation, formation of new bone, contact state of new bone at the interface with implant material.      Elemental mapping method has rarely been used in the field of histological investigation. Electron probe microanalysis (EPMA) is one of the most common apparatus for elemental mapping. Xray scanning analytical microscopy (XSAM) is a new method for the fluorescenct Xray analysis. EPMA and XSAM detect the characteristic Xray emitted from the specimen by irradiation of electron and Xray, respectively       In this study elemental mapping and other imaging methods by EPMA and XSAM as well as optical microscopy were applied for the evaluation of new bone formation around the implant which was inserted in the mandible of rabbits. The results on the Ti implant and Ti/20%HAP FGM implant were then derived and compared each other. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 755-759 溶浸法で製造したエポキシ樹脂緩和ジルコニウム燐酸塩材料の特性評価 Characteristics of Epoxy-Modified Zirconium Phosphate Materials Produced by an Infiltration Process I.M. Low1, S.Yamaguchi2, 中平敦3 and K.Niihara21Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth, 6001 Australia 2大阪大学　産業科学研究所　567 大阪府茨木市美穂が丘8－13京都工芸繊維大学　京都府 I.M. Low1, S.Yamaguchi2, A. Nakahira3 and K.Niihara21Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth, 6001 Australia 2The Institute of Scientific and Industrial Research (ISIR) Osaka University 8-1 Mihogaoka Ibaraki, Osaka 567, Japan  3Department of Materials Science, Kyoto Institute of Technology, Kyoto, Japan  An epoxy infiltration process has been used to fabricate zirconium phosphate with much improved physical and mechanical properties for robust applications in various electrochemical devices. Results show that phase composition, microstructure and properties vary gradually along the depth profile, confirming the functionally-graded character of these materials. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 761-766 溶解―拡散法によるポリ塩化ビニル（PVC）/ポリメタクリル酸傾斜混合の作成と特性 Preparation and Properties of PVC/Polymethacrylate Graded Blends by a Dissolution - Diffusion method 上利泰幸 a, 島田雅之 a, 上田明 a, T. Anan b, 野村良紀 b, 川崎吉包 ba 大阪市立工業研究所　536　大阪府大阪市城東区森之宮１-６－５０b 大阪工業大学　工学部　535　大阪府大阪市旭区大宮5-１６－１ Y. Agari a, M. Shimadaa, A. Uedaa, T. Anan b, R. Nomura b, Y. Kawasaki ba Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536 Jap an b Osaka Institute of Technology, Faculty of Engineering, 5-16-1 , Omiya, Asahi-ku, Osaka 535 Japan  We prepared and characterized PVC/polymethacrylate graded miscible blends by a dissolution-diffusion method, and found that those have high thermal shock resistance and our prediction model can be adopted to those graded structures. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 767-772 ポリイミド/銅傾斜機能材料の準備と特性 Preparation and properties of polyimide/Cu functionally graded material 大森守, 大久保昭, G. H. Kang , 平井敏雄東北大学　金属材料研究所　980-77　宮城県仙台市青葉区片平２丁目１－１ M. Omori, A. Okubo, G. H. Kang and T. HiraiInstitute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-77, Japan  A polymer/Cu functionally graded material (FGM) was prepared from thermosetting polyimide and Cu powders using a spark plasma system. These powders were consolidated at different temperatures. A FGM of Cu and polyimide was prepared under a graded temperature using a graphite die, the diameters of which were different at the top and bottom. A dense polyimide/Cu FGM was formed under the graded temperature.There were no cracks in the FGM prepared by stacking three graded layers. Thermal properties of the thin FGM were measured. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 773-780 曲げ変形なしでの高性能の傾斜機能材料 Smart Functionally Graded Material without Bending Deformation 菱進浩1）、谷順二1）、曽我拓一朗2）1）東北大学　流体科学研究所2）東北大学　大学院 J. Qiu 1), J. Tani 1) and T. Soga 2)1) Institute of Fluid Science, Tohoku University, Japan 2) Graduate School, Tohoku University, Japan  This paper describes a method to reduce the discontinuity of thermal stress in a smart FGM for high temperature. The original smart FGM consists of two layers: one layer of FGM base material and one layer of piezoelectric material (PZT) used as an actuator to reduce the thermal bending deformation. Large stress discontinuity is induced on the interface of the two layers due to the discontinuity of material properties when high voltage is applied to piezoelectric layer. In this study, the stress discontinuity is reduced by introducing a graded piezoelectric layer between the FGM layer and PZT layer. Furthermore, an additional layer is introduced on the low temperature side to measure the bending deformation of the composite FGM so that the deformation induced by time-varying temperature can be actively cancelled by using feedback control. English FUNCTIONALLY GRADED MATERIALS 1996 FUNCTIONALLY GRADED MATERIALS 1996 3 1996-12-31 785-790 グリーン関数を用いた傾斜機能材料の不安定な熱応力の研究 A Study of Unsteady Thermal Stresses of Functionally Graded Materials Using Green's Function Kui Seob Kim a and Deok-Kee Choi ba Department of Aeronautical Engineering, Inha Technical Junior College 253 Yonghyun-dong, Nam-ku, Incheon City, 402-752, Korea b Department of Mechanical Engineering, Dankook University, 8 Hannam-dong, Yongsan-ku, Seoul, 140-714, Korea Kui Seob Kim a and Deok-Kee Choi ba Department of Aeronautical Engineering, Inha Technical Junior College 253 Yonghyun-dong, Nam-ku, Incheon City, 402-752, Korea b Department of Mechanical Engineering, Dankook University, 8 Hannam-dong, Yongsan-ku, Seoul, 140-714, Korea  The purpose of this study is to introduce a method for analyzing the effect of the thermal stress relaxation using functionally graded materials using the modified Green's function solution approach. A typical solution method is to use the Laplace transformation. However, the inverse Laplace transformation is hampered due to the complexity of the solution. In order to solve the unsteady heat conduction equations, the regular perturbation theory is employed. Applying the modified Green's function makes it easy to build the perturbation solution to the problem without performing the difficult inverse Laplace transformation. An one-dimensional infinite plate made of the functionally graded materials is considered to illustrate the present method. English