Thermodynamic modeling, structural and spectroscopic studies of the KNbWO6–KSbWO6–KTaWO6 system

In the present work some structural and thermodynamic features in KNbxSbyTazWO6 solid-state solutions were investigated. A mathematical subregular ternary solutions model is advanced. The compounds have been structurally studied using X-ray diffraction. In particular, structure of individual compounds (KNbWO6, KSbWO6 and KTaWO6) was refined by the Rietveld method (space group Fd3m, Z = 8). IR and Raman spectroscopies were used to assign vibrational bands and determine structural pecularities. The differential scanning calorimetry was applied to measure decomposition temperature of compounds under study and to detect any possible phase transitions.