A straight way toward phase pure complex oxides

Abstract

Great majority of the electroceramic materials to date are complex oxides. Phase purity, high crystallinity and small grains with narrow size distribution are almost always required. Quick nucleation and limited growth are essential for that purpose. The author concentrates himself on a straight way toward this goal by taking three components into account, i.e. (1) active nucleation sites in high concentration, (2) short diffusion path for growth and (3) achievement of kinetic stabilization. Soft-mechanochemical synthesis is one of the best shortcuts to the goal. The main spirit is the incipient chemical reaction at the boundary between dissimilar particles through homogenization of the starting mixture by exerting as small mechanical energy as possible. Case studies are devoted to the syntheses of various complex perovskites, recently carried out in the author's own laboratory.