Structural Phase Transition and Photoluminescence Properties of YF3:Eu3+ Nanocrystals under High Pressure

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• 作者：Chen Gong ; Quanjun Li ; Ran Liu ; Yuan Hou ; Jinxian Wang ; Xiangting Dong ; Bo Liu ; Xiao Tan ; Jing Liu ; Ke Yang ; Bo Zou ; Tian Cui ; Bingbing Liu
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：October 2, 2014
• 年：2014
• 卷：118
• 期：39
• 页码：22739-22745
• 全文大小：407K
• ISSN：1932-7455

文摘

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 ⁵D₀ 鈫?⁷F_1,2,3,4 transition in YF₃:Eu³⁺ nanocrystals emerges obvious changes, which indicate the variation of the local symmetry of Eu³⁺ ions.