Polar Order Evolutions near the Rhombohedral to Pseudocubic and Tetragonal to Pseudocubic Phase Boundaries of the BiFeO3-BaTiO3 System

Abstract

Solid solutions of (1-x)BiFeO3-xBaTiO3 (BF-BT, 0.05 ≤ x ≤ 0.98) were prepared and characterized. It was found that the dielectric constant εm, remnant polarization Pr and piezoelectric coefficient d33 reach their maximum values near the rhombohedral–pseudocubic phase boundary. In particular, the 0.7BF-0.3BT composition shows large polarization (Pr > 20 μC/cm2) and a temperature-stable piezoelectric property (d33 > 100 pC/N when the annealing temperature is lower than ~400 °C). Near the tetragonal–pseudocubic phase boundary, εm and Pr decrease, and the piezoelectric property vanishes when the BF content reaches 4 mol %.

Keywords

• morphotropic phase boundary
• piezoelectric
• BiFeO3