High temperature behavior of zirconium germanates

►Thermal behavior of ZrGeO4 and Zr3GeO8 was studied using the original thermal analysis technique in wide temperature range.►The decomposition occurs via two stages with the formation of intermediate ZrO2-rich solid solution.►The decomposition of zirconium germanates leads to the formation of gaseous GeO2 and solid sintered ZrO2.►The temperature of decomposition is strongly depended on the total gas pressure.

The high temperature behavior of zirconium germanates ZrGeO4 and Zr3GeO8 up to 2300 °C has been studied using the original photoemission thermal analysis technique with the comprehensive physicochemical study of solid and gaseous intermediate and final products. The two-stage process of incongruent sublimation of GeO2 was established and the phase boundary of the homogeneity range for ZrGeO4 and Zr3GeO8 were deduced from the thermal analysis, X-ray diffraction and Raman spectroscopy studies. A high tendency to sintering of the final ZrO2 product is discussed.

Graphical abstractThe decomposition of zirconium germanates leads to the formation of gaseous GeO2 and solid sintered ZrO2 and occurs via two stages with the formation of intermediate ZrO2-rich solid solution.Figure optionsDownload full-size imageDownload as PowerPoint slide