Grain Size Effects in Barium Titanate

Abstract

Due to its high crystallinity and purity, hydrothermal powder was used to study the effects of grain size and density on the dielectric properties of BaTiO3. Curie-Weiss analysis was used to analyze the results as porosity increased. A correlation was found between the level of porosity and the difference between the Curie and Curie-Weiss temperatures, suggesting a limiting value of porosity above which insufficient flux continuity results in anomalous Curie-Weiss behavior. Thermally stimulated polarization currents (pyroelectric currents with biasing field) generated in poled samples were also studied with varying grain size and density and were found to produce ambiguous results for porous samples.