THERMOELECTRIC CONVERSION MATERIAL AND METHOD OF PRODUCING THE SAME, AND THERMOELECTRIC CONVERSION ELEMENT, THERMOELECTRIC CONVERSION MODULE, AND MOVING BODY

• Main Authors: KIKUCHI DAISUKE, MIYOSHI KAZUTOMI, TADOKORO JUN, NISHIKUBO HIDEO, MORI TOMOHIKO, FUJIMURA KOJI
• Format: Patent
• Language: English; Japanese
• Published: 11.10.2018
• Subjects: ALLOYS; CHEMISTRY; COMPOUNDS THEREOF; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a thermoelectric conversion material having high thermoelectric conversion characteristics even when used at high temperatures.SOLUTION: A thermoelectric conversion material contains a Si clathrate compound represented by chemical formula: LnAGaAlSi. In the chemical formula, Ln represents lanthanoid, and A represents Ba or Sr. In the chemical formula, expressions of 0<a≤4, 7.6≤a+b≤8.4, 0≤c≤16, 0≤d≤16, 22<e≤38, and a+b+c+d+e=54 are satisfied, and c and d are not 0 at the same time. The Si clathrate compound has a Si clathrate compound phase, a Si phase, and a lanthanoid-containing phase. When A in the chemical formula is Sr, the proportion α of the Si clathrate compound phase in the Si clathrate compound satisfies 0.35≤α<1, the proportion β of the Si phase satisfies 0<β<0.38, and the proportion γ of the lanthanoid-containing phase satisfies 0<γ<0.65. When A in the chemical formula is Ba, the proportion α satisfies 0.75≤α<1, the proportion β satisfies 0<β<0.14, and the proportion γ satisfies 0<γ<0.25.SELECTED DRAWING: Figure 1 【課題】高温下で使用されても熱電変換特性が高い熱電変換材料を提供する。【解決手段】熱電変換材料は、化学式ＬｎａＡｂＧａｃＡｌｄＳｉｅで表されるＳｉクラスレート化合物を含有する。化学式中のＬｎはランタノイドを示し、ＡはＢａ又はＳｒを示す。化学式は、数式０＜ａ≦４、７．６≦ａ＋ｂ≦８．４、０≦ｃ≦１６、０≦ｄ≦１６、２２＜ｅ≦３８、ａ＋ｂ＋ｃ＋ｄ＋ｅ＝５４を満たし、ｃ及びｄは同時に０とはならない。Ｓｉクラスレート化合物は、Ｓｉクラスレート化合物相、Ｓｉ相、ランタノイド含有相を有し、化学式中のＡがＳｒである場合は、Ｓｉクラスレート化合物中のＳｉクラスレート化合物相の割合αは０．３５≦α＜１、Ｓｉ相の割合βは０＜β＜０．３８、ランタノイド含有相の割合γは０＜γ＜０．６５であり、化学式中のＡがＢａである場合は、割合αは０．７５≦α＜１、割合βは０＜β＜０．１４、割合γは０＜γ＜０．２５である。【選択図】図１