Solid solution of (1-x)Bi0.5Na0.5TiO3-xBaTiO3 have been synthesized via
conventional solid-state reaction route. Structural changes of the
solid-solutions were investigated by using X-ray diffraction, Rietveld
refinement Raman spectroscopy and piezoelectric studies. X-ray diffraction
analysis shows a distinct 002/200 peak splitting appearing at x = 0.07
showing the coexistence of rhombohedral and tetragonal phase. Raman
spectroscopy shows a splitting of (TO3) mode at x = 0.07 confirming the
presence of the morphotropic phase boundary region. The dominant bands in the
Raman spectra are analyzed by observing the changes in their respective peak
positions, widths and intensities as the x increases. The piezoelectric
properties of the solid solution increase with rise in BaTiO3 content and
shows optimum value at x = 0.07 owing to the co-existence of two
ferroelectric phases. Based on these results, it is suggested that the
morphotropic phase boundary in the studied system lies in the composition x =
0.07.