Structural and electrical properties of multiferroic (1−x)BiFeO3−xBi0.5K0.5TiO3 ceramics

Abstract The multiferroic (1−x)BiFeO 3 −xBi 0.5 K 0.5 TiO 3 (BFO–xBKT) ceramic was prepared to investigate the dependence of its structural and electrical properties on BKT component. The ceramic processes a rhombohedral phase at 0 ≤ x ≤ 0.3 and a tetragonal phase at 0.5 ≤ x ≤ 1.0 while it owns the coexistence of these two phases at x∼0.4, according to the XRD patterns and the corresponding simulation with the Reitveld method. Specifically, BFO–0.4BKT shows a saturated polarization of 65.8 μC/cm 2 and an enhanced piezoelectric d 33 of 61 pC/N at room temperature which are much larger than those of other ceramics at x = 0–0.7. The dependence of dielectric constant on temperature suggests a strong relaxor characteristic and a high Curie temperature of ∼462 °C. Furthermore, the poled BFO–0.4BKT ceramic shows radial dielectric resonances at 20–300 °C due to the piezoelectric effect.