Raman scattering and X-ray diffraction investigations of sol-gel derived SBN powders

Sol-gel derived SrxBa1-xNb2O6(SBN) powders were prepared at an annealing temperature of 1200°C. Their structural changes were characterized by Raman spectroscopy and X-ray diffractometry. Changes in the peak position and the relative intensity of the Raman spectra and X-ray patterns were examined for different values of x. Our results suggest that the SBN powders consist of a mixture of orthorhombic phase BaNb2O6(BN) and tetragonal tungsten-bronze phase (TTB) SBN powders for x<0·5, and orthorhombic phase SrNb2O6(SN) and TTB phase SBN powders for x0·5. Pure TTB type SBN powders with x≠0·5, however, were obtained at higher annealing temperatures. A possible formation route of the sol-gel derived SBN powder is discussed.