Behaviour of Diffuse Phase Transition in Ba0.999Pr0.001 TiO3 Ceramics

摘要

Perovskite Ba0.999Pr0.001TiO3 ceramics has been prepared through a solid-state reaction method. Dielectric properties of the doped BaTiO3 (barium titanate) ceramics as a function of temperature at frequencies of 1 kHz, 10 kHz, 100 kHz, and 1 MHz are studied and reported here. Analyzing the empirical parameters, it has been shown that the Pr3+ addition up-shifted the temperature of the maximal dielectric constant to 180 (K) at 1 kHz. The value of the dielectric constant at higher frequencies dropped markedly. Such a marked drop in the value of the dielectric constant at higher frequencies can be explained in terms of interfacial polarization. The high dielectric constant at lower frequencies is due to the build-up of charges at the grain-grain boundary interface which is responsible for the large polarization. The ceramic was subjected to Rietveld refinement for quantitative analysis of the microstructure of the material.