Weakly coupled relaxor behavior of BaTiO3-Bi(Mg1/2Ti1/2)O3 lead-free ceramics

(1-x)BaTiO3-xBi(Mg1/2Ti1/2)O3 (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 δ < 2%) in the temperature range 200–400°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°C. It was found that the energy density of about 0.7 J/cm3 could be achieved at 120°C for x = 0.4 sample, indicating a high energy density.