Thermal Properties and Raman Spectra of Crystalline and Vitreous BaZrF6, PbZrF6, and SrZrF6

Differential thermal analysis and Raman spectroscopic studies have been performed of crystalline and vitreous BaZrF6, PbZrF6, and SrZrF6 compounds in order to examine the thermal properties and the F coordination of Zr. The differential thermal analyses clarified the definite phase transformation characteristics of crystalline BaZrF6, and SrZrF6 and also suggested that the low- and high-temperature modifications are present in PbZrF6 as well as in BaZrF6 and SrZrF6. The Raman spectra of crystalline BaZrF6, PbZrF6, and SrZrF6 were discussed in relation to the F coordination of Zr in fluorozirconate compounds. The crystallization behaviors and Raman spectra of vitreous BaZrF6, PbZrF6 and SrZrF6 revealed that Zr in the vitreous compounds is eight-coordinated by F although small amounts of seven-coordinated Zr may exist in vitreous BaZrF6.