  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.
