Crystal chemistry, Rietveld refinements and Raman spectroscopy studies of the new solid solution series: Ba3−xSrx(VO4)2 (0 ≤ x ≤ 3)

The new solid solution series Ba3−xSrx(VO4)2 (0 ≤ x ≤3) has been synthesized and studied by a combination of X-ray powder diffraction and Raman vibrational spectroscopy. This continuous solid solution crystallise in the hexagonal system with R3¯m space group. The structure has been determined at room temperature from X-ray diffraction by the Rietveld method analysis. It is formed by a 3D network of (Ba/Sr)(1)(VO4)24− layers linked into a crystal network by (Ba/Sr)2+(2) cations. The vibrational spectra of this crystalline orthovanadate solid solution series are interpreted by means of factor group analysis in terms of space group R3¯m (D3d5). Assignments of the V–O vibrational stretching and bending modes, as well as some of the external modes, have been made. While all the modes show a monotonous shift as a function of the composition x, a break in the curves of intensities, full width at half maximum and band areas as a function of x is observed and attributed to the statistical distribution of Ba and Sr ions in the same crystallographic sites.