Grain oriented ceramics, thermoelectric conversion element and production process thereof

Abstract

Grain oriented ceramics constituted of a polycrystalline body of a layered cobaltite in which a {001} plane of each grain constituting the polycrystalline body has an average orientation degree of 50% or more by the Lotgering's method. In this case, the layered cobaltite is preferably a layered calcium cobaltite expressed by the following general formula: {(Ca1−xAx)2CoO3+α} (CoO2+β)y (where A represents one or more elements selected among an alkali metal, an alkaline earth metal and Bi, 0≦×≦0.3, 0.5≦y≦2.0, and 0.85≦{3+α+(2+β)y}/(3+2y)≦1.15). Such grain oriented ceramics are obtained by molding a mixture of the first powder constituted of a Co(OH)2 platelike powder and the second powder constituted of CaCO3 and the like such that a developed plane of the platelike powder is oriented, and by heating the green body at a predetermined temperature.

Dependencies are inferred from the claim text.