High-pressure behaviors of YF3:Eu3+ nanocrystals with an average grain size of 40 nm were investigated by in situ high-pressure synchrotron radiation X-ray diffraction measurements up to 31.1 GPa at ambient temperature. The pressure-induced structural phase transition starts at 11.8 GPa and completes at 23.3 GPa. YF3:Eu3+ nanocrystals with a starting phase of orthorhombic structure transform into a high-pressure phase, which is inferred to be hexagonal structure. The high-pressure structure returned to the orthorhombic phase after release of pressure. The transition pressure is enhanced in nanosized YF3:Eu3+ as compared to submicrometer size samples, which is due to the surface energy differences between submicrometer size and nanosized materials. The nanosized samples of high-pressure phase were easier to compress with smaller bulk modulus than the submicrometer size samples. The photoluminescence properties of YF3:Eu3+ have also been studied in the pressure range from ambient pressure to 25.0 GPa at room temperature. Accompanied by the structure transformation, the Eu3+ ion luminescence from D-5(0) -> (7)F(1,2,3,44)transition in YF3:Eu3+ nanocrystals emerges obvious changes, which indicate the variation of the local symmetry of Eu3+ ions.
Gong, C,Li, QJ,Liu, R,et al. Structural Phase Transition and Photoluminescence Properties of YF3:Eu3+ Nanocrystals under High Pressure[J]. JOURNAL OF PHYSICAL CHEMISTRY C,2014,118(39):22739-22745.
Gong, C.,Li, QJ.,Liu, R.,Hou, Y.,Wang, JD.,...&Liu, BB；刘景.(2014).Structural Phase Transition and Photoluminescence Properties of YF3:Eu3+ Nanocrystals under High Pressure.JOURNAL OF PHYSICAL CHEMISTRY C,118(39),22739-22745.
Gong, C,et al."Structural Phase Transition and Photoluminescence Properties of YF3:Eu3+ Nanocrystals under High Pressure".JOURNAL OF PHYSICAL CHEMISTRY C 118.39(2014):22739-22745.