Phase transformation and fluorescent enhancement of ErF3 at high pressure

Pressure-induced phase transformation and fluorescent properties of ErF 3 were investigated here using in-situ synchrotron X-ray diffraction and photoluminescence up to 32.1   GPa at room temperature. Results showed that ErF 3 underwent a reversible pressure-induced phase transition from the β-YF 3 –type to the fluocerite LaF 3 -type at 9.8   GPa. The bulk moduli B 0 for low- and high-pressure phases were determined to be 130 and 208   GPa, respectively. Photoluminescencent studies showed that new emission lines belonging to the transition of 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , and 4 F 9/2 → 4 I 15/2 appeared during phase transition, suggesting pressure-induced electronic band splitting. Remarkably, significant pressure-induced enhancement of photoluminescence was observed, which was attributed to lattice distortion of the material under high pressure.