Structural, Spectroscopic, and Electronic Properties of Cubic G0-Rb2KTiOF5 Oxyfluoride

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• 作者：Victor V. Atuchin ; Ludmila I. Isaenko ; Valery G. Kesler ; Lei Kang ; Zheshuai Lin ; Maxim S. Molokeev ; Alexander P. Yelisseyev ; Sergey A. Zhurkov
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：April 11, 2013
• 年：2013
• 卷：117
• 期：14
• 页码：7269-7278
• 全文大小：511K
• 年卷期：v.117,no.14(April 11, 2013)
• ISSN：1932-7455

文摘

The G0-Rb₂KTiOF₅ single crystals with dimensions up to nearly a centimeter in size have been prepared by slow solidification method. The elpasolite-related crystal structure of G0-Rb₂KTiOF₅ has been refined by Rietveld method at T = 298 K (space group Fm3̅m, Z = 4, a = 8.880(1) 脜, V = 700.16(2) 脜p>3p>; R_B = 2.66%). The wide optical transparency range of 0.25鈥? 渭m and forbidden band gap of E_g = 3.87 eV have been obtained for the G0-Rb₂KTiOF₅ crystal. Dominating photoluminescence bands at 3.36 and 2.33 eV are related to free and self-trapped excitons, respectively. The electronic structure of G0-Rb₂KTiOF₅ has been evaluated by X-ray photoelectron spectroscopy and calculated with the first-principles methods. A good agreement between theoretical and experimental results has been achieved. Chemical bonding effects have been discussed for all metal ions using binding energy difference parameters and a wide comparison with related oxides and fluorides. The competition between Op>2鈥?/sup> and Fp>鈥?/sup> ions for metal valence electrons has been found.