Microcrystalline BaTiO3 by Crystallization from Glass

Publisher Website
Google Scholar
Abstract
The properties and composition of glasses suitable for crystallization of BaTiO3 are described. The crystallization of certain glasses results in a nearly complete recovery of BaTiO3, besides the feldspar BaAl2SiO3 as a minor phase. The mechanism of crystallization was investigated by thermal analysis, viscosity, and grainsize measurements as a function of the temperature whereas density data were used for evaluation of the BaTiO3 content. Within the range 30 to 60% by volume of BaTiO3 at about 1μ grain size, the measured dielectric constant increased from 100 to 1200. The calculated partial dielectric constant of the Titanate phase at this grain size was about 3500. As the grain size approached 0.1μ, the dielectric constant decreased and became nearly independent of the temperature because of the predominance of surface states. Other effects were attributed to special structural characteristics, such as absence of porosity and clamping of the titanate particles within the microcrystalline matrix. Data are also presented on dielectric constant and loss tangent at different frequencies, dc breakdown strength, dc resistivity, and ferroelectric properties as a function of the grain size of the crystallized material.

This publication has 4 references indexed in Scilit: