Weakly coupled relaxor behavior of BaTiO3-Bi(Mg1/2Ti1/2)O-3 lead-free ceramics

(1-x) BaTiO3-xBi(Mg1/2Ti1/2)O-3 (BT-BMT, 0.3 <= x <= 0.6) ceramics were prepared by the conventional mixed oxide method. Dielectric measurements showed highly diffusive and dispersive relaxor-like characteristics for all compositions. For 0.3 <= x <= 0.4, all these compositions possess a stable dielectric permittivity of approximately 1500 and low loss tangent (tan delta < 2%) in the temperature range 200-400 degrees C, which may have great potential for high-temperature applications. For all samples, examination of the polarization hysteresis behavior shows an obvious linear hysteresis loops at 120 degrees C. It was found that the energy density of about 0.7 J/cm(3) could be achieved at 120 degrees C for x = 0.4 sample, indicating a high energy density.