Structure and Thermal Behavior of Potassium Oxofluorozirconate K₂Zr₃OF₁₂

Oxofluorozirconate K₂Zr₃OF₁₂ was prepared by heating an aqueous suspension of KZrF₅. Its structure and thermal decomposition were studied by thermal analysis (DTA–TG), X-ray powder diffraction (XRD), IR and Raman spectroscopy. The complete hydrolytic decomposition of K₂Zr₃OF₁₂ at 620°C mainly yields a mixture of monoclinic K₂ZrF₆ and ZrO₂ phases. Experimental IR and Raman spectra of oxofluorozirconate K₂Zr₃OF₁₂ and its heating products were measured, systematized, and analyzed. The bands in the experimental spectra were assigned based on the results of quantum-chemical calculations.