Ferroelectric and Piezoelectric Properties of BiFeO₃‐Based Piezoelectric Ceramics

Abstract

Bismuth ferrite‐based bulk ceramics (1– x )Bi 0.97 Sm 0.08 FeO 3 – x BaTiO 3 (BSF– x BT with x = 0.00 FC, x = 0.00 WQ, x = 0.01 WQ, x = 0.03 WQ, and x = 0.05 WQ, where FC is the furnace cooled and WQ is the water quenched) are synthesized by a conventional solid‐state reaction method followed by WQ process. The WQ procedure (compared with FC) dramatically improves the remnant polarization ( P r ) of x = 0.00 ceramic from 11 to 21 μC cm −2 . BT incorporation gradually reduces the coercive field ( E c ) and P r significantly enhances to 28.5 μC cm −2 (at x = 0.03) with fully saturated P – E hysteresis loops. The temperature‐dependent ferroelectric properties reveal that the corresponding P r values improve with the rising temperature; this behavior may be related to the thermally activated domain walls motion. Symmetric and closed electromechanical strain–electric field ( S–E ) curves are obtained with a maximum strain of S max = 0.05% for an optimum composition together with high charge sensor constant ( d 33 = 56 pC N −1 ). The structural and electrical properties of the investigated ceramics are presented in detail.