Low frequency dispersion of ferroelectric hysteresis in 1-3 Pb0.95La0.05TiO3/polymer ferroelectric composites

The ferroelectric hysteresis area as a function of frequency and amplitude of the external electric field, i.e. hysteresis dispersion, is measured for 1-3 Pb0.95La0.05TiO3/Polymer composites by utilizing the Sawyer-Tower circuit. The frequency varies from 10(-2) to 10(4) Hz and the amplitude range is 3-44 kV cm(-1). Given a field amplitude E-0, the hysteresis area <A> first grows and then decays with increasing frequency f. Over the low and high (lower than 10 MHz for device performance) frequency ranges, the area <A> can be separately scaled as <A> proportional to f(1/3)E(0)(2/3) and <A> proportional to f(-1) E-0(2). In addition, the remnant polarization P-r and coercive field E-c as functions off are investigated, respectively, revealing a single-peaked pattern for both P, and Ec. (C) 2002 Elsevier Science B.V. All rights reserved.