Piezoelectric properties of BiFeO3-PbTiO3 ceramics

Polycrystalline (1-x)BiFeO₃-(x)PbTiO₃ ceramics (where x=0.2, 0.3 and 0.5) doped with low concentrations of Sb have been produced via a mixed oxide route. Ceramic disks were thinned and electroded and the high electric field resistivity measured at 100 and 150°C in order to mimic poling conditions. It was found that the high field resistivity was sensitive to composition in undoped materials, and that low dopant concentrations of Sb provided a marked increase in resistivity. This improvement in resistivity increased the maximum permissible poling field by 30% at 150°C for (BiFeO₃)_0.7-(PbTiO₃)_0.3 with 0.2 at% doping compared to the undoped materials.