Phase transition and dielectric properties of nanograin BaTiO3 ceramic under high pressure

Abstract

Temperature dependence of the dielectric constant of nanograin BaTiO3 ceramic has been investigated under hydrostatic pressure σ up to 5GPa. We found that the paraelectric-ferroelectric phase transition temperature TC decreases with σ at a rate of dTC∕dσ=−40.0(±1.1)K∕GPa for coarse-grain ceramic and −34.3(±1.4)K∕GPa for ceramic with 60nm grains. The variation of intergranular stresses with reducing grain size is considered as the main factor causing the decrease of TC and the change of dTC∕dσ.