Large piezoelectricity and high transparency in fine-grained BaTiO3 ceramics

Abstract

Grain size effect is considered as an important factor for the enhancement of dielectric and piezoelectric properties of the barium titanate (BT) ceramics. In this work, we prepared a dense fine-grained BT ceramic using the hot-press sintering method. This fine-grained BT not only exhibits superior electrical properties with a dielectric permittivity of 7200, piezoelectric coefficient of 420 pC/N, and field-induced electrostrain 0.2% at 30 kV/cm but also possesses high transmittance of 30%-60% over a wide range of wavelength from visible to middle infrared radiation spectrum. By a comparative study with the coarse-grained BT, the fine-grained BT is found to have a slight relaxation property due to its large volume fraction of grain boundaries. The coexistence of the fine domains in small grains and the relaxor regions of grain boundaries is responsible for the synchronous enhancement of electrical and optical properties of the fine-grained BT.