Preparation, nonlinear optical properties, and theoretical analysis of the non-centrosymmetric bismuth oxyfluoride, Bi7F11O5

This paper presents the first investigation of the second-harmonic generation (SHG) effect of a metal oxyfluoride. Bi7F11O5 was prepared by the hydrothermal method employing Bi(NO3)(3)center dot 5H(2)O and ZnF2 as raw materials. The compound was characterized by X-ray diffraction, thermogravimetry-differential scanning calorimetry, and Fourier transform infrared, Raman, and diffuse reflectance spectroscopies. Bi7F11O5 is thermally stable up to 400 degrees C. Powder SHG experiments show that the SHG efficiency of Bi7F11O5 is about 2.7 times that of KH2PO4 (KDP); moreover, the developed material is type I phase-matchable. Bi7F11O5 has a middle-ultraviolet absorption edge (<300 nm) and a wide transparency range up to the mid-infrared region (12.5 mu m). An analysis of the dipole moments of the polyhedra and theoretical density functional theory calculations were also performed to clarify the structure-properties relationships of Bi7F11O5. (C) 2015 Elsevier B.V. All rights reserved.