Preparation of PbTiO<sub>3</sub>-Based Conductive Ceramic Powders by Gaseous Penetration of Rare Earth

Abstract

The new type PbTiO3 based ceramic conductive powders were prepared with a special technology, gaseous penetration, which is making rare earth La penetrate into PbTiO3 powders in the gaseous state at high temperature. Through XRD analysis, it is found that there are some new compounds such as LaTiO3 and LaTi3O49 formed after penetration of La, which indicates that the gaseous penetration made La element enter PbTiO3 powders and the complex reactions took place during the penetration process. Through SEM, it can be deduced that the rare earth elements occupied the atom vacancies, formed the new phases and made the grains of La-penetrated PbTiO3 based powders become smaller and finer with less pores and appeared as dispersing structure. All these led to a significant change in electric conductivity, and when the La3+ content in the solvent was 0.02, the penetration temperature was 950°C and the penetration time was 4h, the resistivity at room temperature was the smallest, which decreased from 8.3×108Ω.m to 8.2×10-4Ω•m.