Perovskite Formation Process in Pb(Ti·Zr)O3 Ceramics Containing SiO2

Abstract

Influence of SiO2 addition on formation process of Pb(Ti·Zr)O3 solid solution was studied. Powdered PbO, TiO2, ZrO2 and SiO2 were used as raw materials. The process was determined from the variation of X-ray diffraction patterns and that of dilatometric dimensional change with heating temperatures. If the materials excluding SiO2 were mixed, Pb(Ti·Zr)O3 was synthesized, passing through formations both of PbTiO3 and PbZrO3. However, when the materials including SiO2 were mixed, the PbZrO3 formation was suppressed, accompanying by a decrease of Pb(Ti·Zr)O3 formation temperature. The difference seems to be caused by the appearance of a liquid phase formed by the co-existence of SiO2 and PbO, which occurs during the Pb(Ti·Zr)O3 formation process. Reaction observed at the contact surface of two green compacts, consisting of SiO2-PbO as well as of Pb(Ti·Zr)O3, was in line with the assumption. © 1973, Japan Society of Powder and Powder Metallurgy. All rights reserved.