yrammuS 要概岡本佳比古13Yoshihiko OKAMOTO櫻井 庸明14Tsuneaki SAKURAI幾何学的にフラストレートした籠状構造を活用した高効率熱電変換材料の開発(2016採択)Geometrically-frustrated cage compounds as high-performance thermoelectric materials(Project 2016)有機半導体-異種材料界面における本質的電荷輸送特性評価手法の開拓(2016採択)Noncontact Evaluation Technique of Intrinsic Charge Carrier Transporting Property at Heterointerfaces(Project 2016)27Rep. Grant. Res., Asahi Glass Foundation (2018)The purpose of this study is to develop the micro-cantilever beam technique to evaluate the fracture property in meso-scale, and to measure the meso-scale fracture properties of various materials. By us-ing micro-cantilever beam specimens with various size and shape, the suitable geometry to measure the meso-scale fractur properties reasonably was clarified. As a result of measurement of the fracture properties in the compressive layer of the ion-exchanged soda-lime glass, it was shown that the strength in the compressive layer was higher thant that of as-recieved glass because of the improve-ment of the Young's modulus. The degradation mechanism of Si3N4 ceeramic surface layer in contact with molten Al was also elucidated by using the micro-cantilever beam specimens. Furthermore, the grain boundary strength of SiC porous ceramics was measured directly using micro-cantilever beam specimens prepared at the grain boundary. It was found that the grain boundary strength was almost the same as the ideal stregth, plastic deformation occured before fracture, and the strength of the bulk SiC porous ceramics was able to be explained using the measured grain boundary strength.遷移金属原子がパイロクロア格子を組んだ化合物に現れうる高エントロピー電子相において，従来材料を超える高い熱電変換性能が現れる可能性に着目し，β型パイロクロア構造をもつ酸化物CsW2O6を中心として新しい熱電変換材料の開拓を行った．CsW2O6単結晶・焼結体試料を用いた熱電特性の測定により，CsW2O6の金属相が，金属としては大きな熱起電力とガラス並みの小さい熱伝導率を示すことが明らかになった．また，一次元鎖が幾何学的にフラストレートした三角格子を形成したM4SiTe4 (M = Ta, Nb)ウィスカー結晶において，現在使用される実用水準を超える大きな出力因子が現れることを明らかにした．I studied thermoelectric properties of geometrically frustrated cage compounds such as β-pyrochlore oxide CsW2O6. A geometrically frustrated pyrochlore lattice made of W atoms in CsW2O6 is expected to give rise to a high entropy phase, which may show high thermoelectric performance exceeding the practical level. Thermoelectric property measurements using CsW2O6 single crystals and sintered samples indicate that large thermoelectric power for a metal and low thermal conductivity comparable to those of amorphous materials appear in the metallic phase of CsW2O6. I also found that the whisker crystals of M4SiTe4 (M = Ta, Nb), where M4SiTe4 chains form a geometrically frustrated triangular lattice, show very large thermoelectric pow-er factor exceeding those of practical thermoelectric materials.著者らが開発したField-Induced Time-Resolved Microwave Conductivity（FI-TRMC）法は，電界誘起により生成させた電荷キャリアに対し，マイクロ波を用いてその輸送特性を評価する非接触法であり，半導体/絶縁体界面における局所空間領域のより材料本質的な移動度が測定可能である．本研究では，p型材料に加えてn型有機半導体を対象に，その局所電子移動度を空気下で評価し，10 cm2 V–1 s–1を超え
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