Electrical properties of Ca-modified Na0.5Bi0.5TiO3-BaTiO3 ceramics

Ceramics in the system (1-x)Na0.5Bi0.5TiO3-xBa0.80Ca0.20TiO3 demonstrate a phase boundary between pseudo-cubic and tetragonal at 0.1 <x<0.2. There was a gradual convergence in the temperatures of a frequency-dependent inflection and peak in relative permittivity-temperature plots with increasing x: for x=0.5 and 0.6, normal relaxor-like behaviour was observed, with T m ~150 °C (1 kHz). Constriction in the polarisation-electric field hysteresis loops for the phase boundary composition x=0.1 was consistent with an electric field-induced phase transition, giving rise to an electromechanical strain, ~0.25 % at 40 kV/cm and high-field d 33* ~640 pm/V.