XRD, Raman and electrical studies on the (1−x)(Na0.5Bi0.5)TiO3−xBaTiO3 lead free ceramics

Lead-free piezoceramics (1−x)Bi0.5Na0.5TiO3–xBaTiO3 (x = 0.00, 0.03, 0.05, 0.065, 0.07, 0.08 and 0.10) have been prepared by the conventional solid reaction method and their structure and electrical properties were systematically investigated. X-ray diffraction analysis indicates that a solid solution is formed in (1−x)BNT–xBT ceramics with presence of a morphotropic phase boundary (MPB) between rhombohedral and tetragonal phases in the composition range x = 0.065–0.07 at room temperature. The distinct changes of the Raman spectra with increasing of BaTiO3 content which were correlated with XRD results were observed. It was found that the MPB compositions show improved electrical properties and reach preferred values at x = 0.065; the piezoelectric constant d33 and electromechanical coupling factor kt are 150 pC/N and 51% respectively.