Grain Size Effects on the Properties of MPB-BSPT Ceramics under Uniaxial Compressive Stress and Electric Field

Abstract

(1-x)BiScO3-xPbTiO3 (BSPT) ceramics with grain size range of 0.5~2.5 μm at morphotropic phase boundary (MPB) were prepared by conventional sintering method. The grain sizes of the ceramics were determined by scanning electron microscopy (SEM). The grain size effects on the structure of BPST ceramics were analyzed by X-ray diffraction (XRD). The ferroelectric hysteresis response under various uniaxial compressive stress of up to 150 MPa was measured. With increasing the mechanical uniaxial stress, the remnant polarization (Pr) and the coercive field (Ec) were significantly reduced. The direct current (DC) bias dependence of capacitance of MPB-BSPT ceramics with different grain sizes was compared. The results indicated that the domain switching was prevented by the compressive stress. The domain size and domain structure were influenced by the grain size. The domain switching under uniaxial stress and electric field became more difficult due to the decrease of grain sizes. The grain size as well as the domain size played a key role in the properties under external uniaxial compressive stress and electric field.