Effects of CuO, Cr2O3 and Fe2O3 Doping on Phase Formation, Microstructure and Electric Properties of (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 Ceramics

Abstract

The effects of CuO, Cr₂O₃ and Fe₂O₃ doping on the phase formation, microstructure and electric properties of (Ba_0.85Ca_0.15)(Ti_0.90Zr_0.10)O₃ (BCTZ) ceramics prepared by the combustion method were studied. Glycine was used as fuel and the ratio of raw material to fuel was 1:1.11. All samples were calcined and sintered at the temperatures of 1050??C and 1450??C for 2 h, respectively. The XRD data showed a pure perovskite structure with the coexistence of orthorhombic and tetragonal phases in all samples. The grain morphology of the ceramics exhibited irregular polyhedron shape and the average grain size was in the range of 15.5 to 42.8 ??m. Samples of the BCTZ ceramics modified with Cu exhibited the highest density (5.79 g/cm³), the highest maximum dielectric constant (e_c=12514) and good ferroelectric properties (P_r=12.6 ??C/cm² and E_c=2.5 kV/cm).

Keywords: phase formation, microstructure, dielectric properties, ferroelectric properties