Ferroelectric and Piezoelectric Properties of BiFeO3-Based Piezoelectric Ceramics

Bismuth ferrite-based bulk ceramics (1-x)Bi0.97Sm0.08FeO3-xBaTiO(3) (BSF-xBT 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 mu C cm(-2). BT incorporation gradually reduces the coercive field (E-c) and P-r significantly enhances to 28.5 mu C 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.