Polar Bismuth Selenite Iodate Oxide BiSeIO 6 with Three Types of Lone Pair Cations in One Structure

• Published in: Inorganic chemistry Vol. 62; no. 6; pp. 2887 - 2893
• Main Authors: Geng, Lei, Li, Wenfei, Zhu, Baozhu, Ma, Shihua, Liu, Baotong, Jiang, Kaiyue, Lu, Hongyan, Meng, Changyu
• Format: Journal Article
• Language: English
• Published: United States 13.02.2023
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.2c04323

Novel bismuth selenite iodate oxide BiSeIO was synthesized in a mild hydrothermal condition. BiSeIO was crystallized in the polar space group 2 of an orthorhombic system. The crystal structure features a three-dimensional framework composed of three types of lone pair cations with distorted BiO polyhedra, SeO pyramids, and IO pyramids in one structure. Interestingly, BiSeIO exhibits a strong and phase-matchable second-harmonic generation (SHG) of ∼6 times that of KH PO (KDP). Dipole moment analysis shows that all three local acentric groups of BiO , SeO , and IO cooperatively contribute to the large macroscopic polarization and thereby strong SHG efficiency of BiSeIO . In addition, BiSeIO has a broad transparency range from 0.35 to 11 μm, indicating its promising nonlinear optical applications from visible to mid-infrared bands.