A Trial to Construct an Expert System for the Formation of Perovskite-Type Mixed Oxides

Abstract

An expert system, which judges what kinds of perovskite-type mixed oxides will be formed in the ternary system of metallic elements, has been constructed as a part of a system for ceramic material design. In this system, formation was judged on the basis of crystallographic knowledge and databases which were collected from the literature: This system has two kinds of databases, all perovskites in the literature and ionic characters of elements. Conditions used to evaluate the stability of perovskites are, (1) charge balance, (2) ionic radius, (3) the stability of each ion and oxygen vacancy in perovskites, (4) stability of each ion of atmosphere, (5) acidbasicity, (6) the properties of d electrons of transition metals.