Microstructure, electrical properties, strain and temperature stability of (K, Na, Li)(Nb, Ta)O3 ceramics: The effect of BiFeO3 additive

To improve the temperature stability of (K, Na, Li) (Nb, Ta)O3 (KNLNT) ceramics, the effect of BiFeO3(BFO) additives on the phase structure, microstructure, electrical properties, strain and temperature stability was investigated and evaluated. The value of To–t decreased to near or below room temperature. It was calculated that the average grain size was 2.5, 2.3, 1.9, 1.7 and 1.3 µm when x was increased x from 0.0 to 0.8 mol%. The diffuse phase transition behavior was first reduced and then enhanced by adding BFO additive. The results indicated that the (1−x)KNLNT–xBFO ceramics exhibited favorable electrical properties (d33=261 pC/N, kp=0.58, Pr=23.7 μC/cm2, Ec=22.9 kV/mm and strain=0.3%) at x=0.4 mol%. The KNLNT–0.4 mol%BFO ceramics had good temperature stability from room temperature up to 100 °C. The results represented a new direction for developing electrostrictive material that possesses high piezoelectric properties, large strain and good stability.