The crystalline solid europium germanate NaEuGeO4 was prepared under hydrothermal conditions. The in-situ photoluminescence spectroscopic measurement and the synchrotron X-ray diffraction analysis in a diamond anvil c...The crystalline solid europium germanate NaEuGeO4 was prepared under hydrothermal conditions. The in-situ photoluminescence spectroscopic measurement and the synchrotron X-ray diffraction analysis in a diamond anvil cell （DAC） under high pressure were performed to study the pressure-induced phase transition of NaEuGeO4 as well as changes of the luminescent properties of Eu3＋ ions. Photoluminescence spectroscopic studies revealed that a phase transition occurred at a pressure range of 6.5--10 GPa and the high-pressure phase of NaEuGeO4 （NaEu- GeO4-HP） was still stable when the pressure raised up to about 20 GPa. As the pressure was released, the spectra returned to the original state, revealing that the pressure-induced phase transition is a completely reversible process. The synchrotron X-ray diffraction analysis demonstrated that the structure of NaEuGeO4 transformed to an uniden- tified phase NaEuGeO4-HP at a pressure higher than 10 GPa, and the phase transition is reversible. This result is consisted with that obtained by photoluminescence spectra analysis.展开更多
文摘The crystalline solid europium germanate NaEuGeO4 was prepared under hydrothermal conditions. The in-situ photoluminescence spectroscopic measurement and the synchrotron X-ray diffraction analysis in a diamond anvil cell （DAC） under high pressure were performed to study the pressure-induced phase transition of NaEuGeO4 as well as changes of the luminescent properties of Eu3＋ ions. Photoluminescence spectroscopic studies revealed that a phase transition occurred at a pressure range of 6.5--10 GPa and the high-pressure phase of NaEuGeO4 （NaEu- GeO4-HP） was still stable when the pressure raised up to about 20 GPa. As the pressure was released, the spectra returned to the original state, revealing that the pressure-induced phase transition is a completely reversible process. The synchrotron X-ray diffraction analysis demonstrated that the structure of NaEuGeO4 transformed to an uniden- tified phase NaEuGeO4-HP at a pressure higher than 10 GPa, and the phase transition is reversible. This result is consisted with that obtained by photoluminescence spectra analysis.
