Structural evolution and dielectric response of (1-x)BiFeO3-xSrTiO3 ceramics

Pure phase (1-x)BiFeO3-xSrTiO(3) (0 <= x <= 0.9) ceramics were synthesized by a conventional solid reaction method. The crystal structure of the solid solution changes from rhombohedral to pseudocubic at x = 0.2-0.4, then to cubic at x = 0.8. Several compositions with the pseudocubic structure have large dielectric permittivity, low dielectric loss, and flat temperature coefficients of capacitance (from room temperature up to 400 degrees C). As a result, they are the promising lead-free materials for capacitors of power electronics at high-temperature.