ABOUT THE MECHANISM OF THE SOLID-WAY SYNTHESIS OF BARIUM METATITANATE - INDUSTRIAL CONSEQUENCES

Barium metatitanate BaTiO3 is the main component of the dielectric material of class 2 ceramic capacitors. The solid state reaction between BaCO3 and TiO2 is still one of the main industrial ways for the BaTiO3 preparation. The aim of the paper is to propose a coherent set of interfacial reactions in order to explain all the experimental results previously published about this well known solid state reaction. The paper gives at first a summary of the main experimental results. Then all the interfacial reactions at the various stages of the advancement are proposed. All these reactions involve the same main point defects in BaTiO3 which are barium and oxygen vacancies. It has been supposed that they are also the involved defects in the intermediate phase Ba2TiO4. Improvements of the BaTiO3 solid way synthesis are examined. © 1990.