Structure and electrical properties of 0.85(Bi0.5Na0.5)TiO3-0.12BaTiO3-0.03SrTiO3 ferroelectric ceramics

The crystal structure, domain structure and the electrical properties of 0.85(Bi0.5Na0.5)TiO3-0.12BaTiO(3)-0.03SrTiO(3) ceramics have been investigated. Rietveld refinement with Fullprof software was used to analyze the X-ray diffraction data and a two-phase coexistence between a monoclinic (Cm) phase and a tetragonal phase (P4mm) best describes the diffraction patterns from 25 degrees C to 100 degrees C. Results from X-ray diffraction and dielectric measurements show that the Curie temperature is between 220 degrees C and 240 degrees C. The domain structure shows the presence of both non-180 degrees domain walls and 180 degrees domain walls similar to that already observed in Pb(ZrxTi1-x)O-3 ceramics. The hysteresis curves show that the coercive field decreases with increasing temperature up to 100 degrees C. The piezoelectric charge coefficient (d(33)*) at 25 degrees C is 167 +/- 25 pm/V and increased only slightly with temperature up to 100 degrees C. These properties make this piezoelectric ceramic material suitable for ultrasonic transducers, sonars, hydrophones and other applications. (C) 2013 Elsevier Ltd. All rights reserved.