X-ray absorption and Raman spectroscopy studies of tungstates solid solutions ZncNi1-cWO4 (c=0.0-1.0)

Abstract

The influence of thermal disorder and static distortions on the local structure in microcrystalline solid solutions of tungstates ZncNi1-cWO4 with c=0.0-1.0 was investigated using temperature-dependent (10-300 K) x-ray absorption spectroscopy (XAS) at the W L3-edge. In addition, the vibrational properties of the solid solutions were studied by Raman spectroscopy. Our results indicate that the formation of solid solutions is accompanied by strong structural relaxations leading to the changes in the [WO6] octahedra distortions, which, in turn, affect the vibrational properties of tungstates. In particular, the frequency and band width of the highest W-O stretching mode at about 900 cm-1 show distinct composition dependence, following the local structure modifications as revealed by XAS.