Enhanced relaxor behavior and thermal- and frequency-insensitive strain of (Na0.5Bi0.5)0.93Ba0.07Ti1 − x(Mn1/3Nb2/3)xO3 ceramics

(Na0.5Bi0.5)0.93Ba0.07Ti1 − x(Mn1/3Nb2/3)xO3 ceramics (x = 0–0.02) were prepared, and their structure and property were investigated systematically. (Mn1/3Nb2/3)4+ doping shifts ferroelectric–relaxor transition temperature (TF–R) toward low temperature. Thus, ferroelectric order is suppressed and relaxor behavior is enhanced monotonously, as further evidenced by composition-dependent electrical properties and domain evolution from labyrinthian to nanodomain. As a result, the x = 0.010 ceramic yields a large room temperature field-induced strain of 0.37%, especially the strain is temperature- and frequency-insensitive with a variety of 4.3% and 4.1% in the ranges of 25–125 °C and 0.5–10 Hz, respectively. This work suggests that the low content (Mn1/3Nb2/3)4+ complex cation doping is an alternative method to effectively tune the electrical properties of Na0.5Bi0.5TiO3-based ferroelectrics.