[GaF(H ₂O)][IO ₃F]: a promising NLO material obtained by anisotropic polycation substitution†

Abstract

A novel salt-inclusion fluoroiodate [GaF(H ₂O)][IO ₃F] derived from CsIO ₂F ₂ was ingeniously obtained through anisotropic polycation substitution. Because the catenulate [GaF(H ₂O)] ²⁺ framework serves as a template for the favorable assembly of the polar [IO ₃F] ²⁻ groups and contributes to the nonlinear coefficient, [GaF(H ₂O)][IO ₃F] exhibits a greatly improved second-harmonic generation (SHG) effect of 10 times that of KH ₂PO ₄ (KDP) and a considerable band gap of 4.34 eV compared to the parent compound CsIO ₂F ₂ (3 × KDP, 4.5 eV). Particularly, to the best of our knowledge, [GaF(H ₂O)][IO ₃F] has the largest laser-induced damage threshold (LDT) of 140 × AgGgS ₂ of the reported iodates. All these results signify that [GaF(H ₂O)][IO ₃F] is a promising nonlinear optical (NLO) crystal. This work also proposes that anisotropic polycation substitution is an effective approach to optimize the SHG effect and develop excellent NLO materials.

Abstract

A novel salt-inclusion fluoroiodate nonlinear optical material, [GaF(H ₂O)][IO ₃F], is derived from CsIO ₂F ₂ through polycation substitution, and it exhibits an intense SHG effect of 10 times that of KH ₂PO ₄ and improved overall performance.