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 t emperature of 1200 degrees C. Their structural changes were characterized b y Raman spectroscopy and X-ray diffractometry. Changes in the peak position and the relative intensity of the Raman spectra and X-ray patterns were ex amined for different values of x. Our results suggest that the SBN powders consist of a mixture of orthorhombic phase BaNb2O6 (BN) and tetragonal tung sten-bronze phase (TTB) SBN powders for x < 0.5, and orthorhombic phase SrN b2O6 (SN) and TTB phase SBN powders for x > 0.5. Pure TTB type SBN powders with x not equal 0.5, however, were obtained at higher annealing temperatur es. A possible formation route of the sol-gel derived SBN powder is discuss ed. (C) 1999 Elsevier Science Limited. All rights reserved.