Structures and temperature-dependent electrical properties in Ba0.8Sr0.2TiO3-BiAlO3 electrostrictive ceramics

Lead-free piezoceramics of (1 − x)Ba0.8Sr0.2TiO3-xBiAlO3 [(1 − x)BST-xBA (0 ≤ x ≤ 0.12)] have been synthesized and the structures and properties have been investigated systemically. X-ray diffraction patterns indicated that the solid solution limit is close to x = 0.04, and a morphotropic phase boundary (MPB) separating tetragonal and pseudocubic phases exists near x = 0.02. The ferroelectricity weakens monotonously with increasing x, accompanied by weakened butterfly shaped bipolar strain-electric field curves. The temperature dependent properties of the composition with x = 0.02 have been typically investigated, showing that with increasing temperature, the ferroelectricity tends to be weakened. Pure electrostrictive effect has been found in the compositions with x = 0.02 and 0.03 close to room temperature temperature. Based on the results, the effects of BA on structures and electric properties were discussed.