Dielectric, ferroelectric, and depolarization properties of B-site manganese-doped 0.925(Bi0.5Na0.5)TiO3–0.075BaTiO3 solid solutions

Abstract (Bi0.5Na0.5)0.925Ba0.075(Ti1−xMnx)O3 (x=0, 0.2, 1.0, and 2.0 mol%) ceramics were prepared by solid-state-reaction method to study dielectric, ferroelectric, and depolarization properties. The manganese (Mn) doping can suppress dielectric permittivity and increase relaxor behavior. Coercive field (Ec) increases, while remanent polarization (Pr) decreases as the Mn content increases. Pr exhibits discontinuous anomalies as a function of temperature in all compositions, implying a polarization reorganization of local domains. The depolarization temperature (Td) reaches the highest value (~152 °C) in 0.2%Mn, and decreases as MnO2 content increases. The increased Td in 0.2%Mn is due to two-phase coexistence and structural thermal stability induced by Mn ions. This work suggests that the moderate Mn doping can enhance Td in lead-free piezoceramics for applications at elevated temperatures.