Dielectric and Raman studies of Ba_0.06(Na_1/2Bi_1/2)_0.94TiO₃–NaNbO₃ ceramics

In this work the X-ray diffraction, scanning electron microscopy, Raman and dielectric studies of lead free perovskite (1 – x)Ba_0.06(Na_1/2Bi_1/2)_0.94TiO₃–xNaNbO₃ (0 ⩽ x ⩽ 1.0) ceramics, prepared using a standard solid state reaction method, were investigated. X-ray diffraction studies of all the ceramics suggested the formation of single phase with crystal structure transforming from rhombohedral-tetragonal to orthorhombic symmetry with the increase in NaNbO₃ content. Raman spectra also confirmed the formation of solid solution without any new phase. Dielectric studies showed that the phase transition is of diffusive character and diffusivity parameter decreases with increasing NaNbO₃ content. The compositional fluctuation was considered to be the main cause of diffusivity.