摘要
Raman and luminescence studies on the phase transition of europium orthoniobates （EuNbO4） under high pressure were performed. The pressure dependent Raman spectra revealed that an irreversible phase transition from monoclinic phase to M＇-fergusonite phase of EuNbO4 occurred at 7.3 GPa, and the two phases coexisted over a pressure range from 7.3 to 13.7 GPa. An obvious discontinuity on luminescence intensity ratio between 5D0 →7F2 and 5D0→7F1 transitions was observed with increasing pressure, in- dicating also that a phase transition occurred at 7.3 GPa, which was in agreement with the high pressure Raman spectra data. Mean- while, the Raman and luminescence spectra in the temperature range of 20--300 K showed the structure stability at low temperatures.
Raman and luminescence studies on the phase transition of europium orthoniobates （EuNbO4） under high pressure were performed. The pressure dependent Raman spectra revealed that an irreversible phase transition from monoclinic phase to M＇-fergusonite phase of EuNbO4 occurred at 7.3 GPa, and the two phases coexisted over a pressure range from 7.3 to 13.7 GPa. An obvious discontinuity on luminescence intensity ratio between 5D0 →7F2 and 5D0→7F1 transitions was observed with increasing pressure, in- dicating also that a phase transition occurred at 7.3 GPa, which was in agreement with the high pressure Raman spectra data. Mean- while, the Raman and luminescence spectra in the temperature range of 20--300 K showed the structure stability at low temperatures.
基金
Project supported by National Natural Science Foundation of China(11074232,11274288,21002097,11304300,11174265)
the National Basic Research Program of China(2011CB932801,2009CB939901,2012CB933702)
Ministry of Education of China(20123402110034)
