Formation of fluorozirconate glasses under high pressures

Two ternary and one multicomponent fluorozirconate glasses have been prepared by melt quenching under pressures up to 25 kbar in a piston cylinder apparatus. Infrared and Raman spectra of these glasses were recorded at ambient conditions and were similar to the corresponding spectra of fluorozirconate glasses prepared at ambient pressure. However, a decrease in the frequency of an intense high frequency Raman band indicated that the coordination number of zirconium had increased with increasing quench pressure. In situ Raman spectra at pressures up to 90 kbar were recorded at ambient temperature using a diamond anvil cell. A reversible increase in the frequency of the strong Raman band was observed both for the glass quenched at ambient pressure and that formed at 25 kbar. The initial rate of frequency increase was greater for the high pressure glass, confirming that configurational changes had been quenched in the sample prepared at high pressure.