Wet forming, sintering behavior, and dielectric properties of BaTi0.8Zr0.2O3

Abstract

Density, grain size, lattice parameter, and dielectric properties were measured on BaTi0.8Zr0.2O3 sintered at 1100–1600 °C. The hydrothermally prepared BaTi0.8Zr0.2O3 particles of 128 nm diameter were consolidated by filtration of 2-methoxyethanol suspensions and subsequently compressed by isostatic pressing under a pressure of 294 MPa to form a uniform microstructure of high density (52% of the theoretical density). These green compacts were sintered to a relative density of above 99% in the temperature range from 1350 to 1600 °C where rapid grain growth to above 30 μm occurred. Increase of sintering temperature was accompanied by the increase of lattice parameter and dielectric constant of BaTi0.8Zr0.2O3 at room temperature. The sintered BaTi0.8Zr0.2O3 showed a diffuse phase transition from paraelectric (higher temperature) to ferroelectric state (lower temperature) at 32 °C.