High temperature thermoelectric material and its production method

摘要

An excellent thermoelectric material for high temperature use made of a sintered body of a relative density of at least 75 % consisting mainly of cobalt . antimony compounds having an elemental ratio Sb/(Co + any additives) = x of 2.7 < x < 3 is produced by a method of firing a shaped body of powders consisting mainly of cobalt and antimony in a non-oxidizing atmosphere under an environmental pressure, wherein the shaped body before the firing is constituted from crystal phases composed of a cubic crystal system compound CoSb3 (A phase), a monoclinic crystal system compound CoSb2 (B phase) and a hexagonal crystal system compound CoSb (C phase), and constitutional ratio of these crystal phases is (IB + Ic)/(IA + IB + Ic)< 0.15 (wherein, IX (X is A, B or C) is a relative intensity by X-ray diffraction).