We investigate high-pressure induced phase transitions of YF3 and Eu-doped YF3 (YF3:Eu3+) by using the angular dispersive synchrotron X-ray diffraction technique at room temperature. It is found that the starting orthorhombic phase transforms into a new high-pressure phase which is identified as hexagonal structure in both YF3 and YF3:Eu3+. The high-pressure structure of YF3 and YF3:Eu3+ returned to the orthorhombic phase after release of pressure. The photoluminescence properties of YF3:Eu3+ have also been studied under high pressure up to 25 GPa. The Eu3+ ion luminescence lines of D-5(0) -> F-7(1,2,3,4) transition originating from the orthorhombic phase transform into another group of luminescence lines of hexagonal phase under high pressure, which reveals the pressure-induced structural transition of YF3:Eu3+. The relative luminescence intensity ratio of D-5(0) -> F-7(2) to D-5(0) -> F-7(1) transitions of the Eu3+ ions is found to increase with increasing pressure before phase transition and decrease after transition finished, indicating reducing and enhancing of the symmetry around the Eu3+ ions, respectively.
Gong, C,Li, QJ,Liu, R,et al. Structural phase transition and photoluminescence properties of YF3 and YF3:Eu3+ under high pressure[J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS,2013,15(45):19925-19931.
Gong, C.,Li, QJ.,Liu, R.,Hou, Y.,Wang, JX.,...&Liu, BB；刘景.(2013).Structural phase transition and photoluminescence properties of YF3 and YF3:Eu3+ under high pressure.PHYSICAL CHEMISTRY CHEMICAL PHYSICS,15(45),19925-19931.
Gong, C,et al."Structural phase transition and photoluminescence properties of YF3 and YF3:Eu3+ under high pressure".PHYSICAL CHEMISTRY CHEMICAL PHYSICS 15.45(2013):19925-19931.