Selenite bromide nonlinear optical materials Pb<sub>2</sub>GaF<sub>2</sub>(SeO<sub>3</sub>)<sub>2</sub>Br and Pb<sub>2</sub>NbO<sub>2</sub>(SeO<sub>3</sub>)<sub>2</sub>Br: synthesis and characterization
Huanke Zhao, Pifu Gong, Xinyuan Zhang, Zheshuai Lin, Zhanggui Hu, Yicheng Wu
Abstract
Two new isomorphic selenite bromides, namely Pb2GaF2(SeO3)2Br (1) and Pb2NbO2(SeO3)2Br (2), were synthesized by mild hydrothermal reactions. These two compounds crystallize in the noncentrosymmertric space group P21 and feature 3D structures consisting of 1D (Pb2Br)3+ cationic chains and 2D [Ga2F4(SeO3)4]6-/[Nb2O4(SeO3)4]6- anonic chains. As measured, 1 and 2 are phase-matchable and exhibit excellent second harmonic generation (SHG) responses of 4.5 and 1.4 times that of KDP, respectively. Moreover, these two compounds possess wide bandgaps (>3.17 eV) and high thermal stabilities (>425 °C), indicating their suitable performances as potential nonlinear optical materials. First-principle density functional theory (DFT) calculations were also performed to explicate the structure-property relationship.