Na4Yb(CO3)3F: A New UV Nonlinear Optical Material with a Large Second Harmonic Generation Response

A new nonlinear optical crystals fluoride carbonate, Na4Yb(CO3)(3)F, has been synthesized by mild hydrothermal method. The Na4Yb(CO3)(3)F crystallizes in the noncentrosymmetric space group Cc (no. 9) with the lattice parameters a = 8.018(3), b = 15.929(5), c = 13.950(5) angstrom and beta = 101.425(6)degrees. The compound Na4Yb(CO3)(3)F has a high density of [CO3] groups. The structure can be described as one-dimensional [Na5Yb(CO3)(2)F-2] chains connected by [CO](3) groups, forming an intricate three-dimensional (3D) framework. Other Na+ and Yb3+ cations are located in the cavities of 3D network. The powder second harmonic generation (SHG) measurement shows that Na4Yb(CO3)(3)F features a large SHG response, about 4.3 times that of KH2PO4 (KDP), and is a phase-matchable material. In addition, its UV-Vis-NIR diffuse reflectance spectral data indicate that Na4Yb(CO3)(3)F has a large optical gap about 4.72 eV, which corresponds to the UV cut-off edge of 263 nm.