ZrF<sub>2</sub>(IO<sub>3</sub>)<sub>2</sub> and RbGaF<sub>3</sub>(IO<sub>3</sub>): Two Promising Birefringent Crystals Featuring 1D Metal-Fluoride Cationic Chains and Wide Bandgaps
Jin Chen, Ke‐Zhao Du
Abstract
Herein, two novel metal iodate-fluorides, ZrF2(IO3)2 and RbGaF3(IO3), have been prepared via hydrothermal reactions. In the structure of ZrF2(IO3)2, neighboring Zr atoms are connected via a pair of F atoms into the one-dimensional (1D) [ZrF2]2+ cationic chain, which further attaches two iodate groups forming 1D ZrF2(IO3)2, whereas the 1D cationic chain in RbGaF3(IO3) is [GaF]2+, formatted by the bridging of Ga3+ cations and axial F– anions, which further connect with one iodate group and two terminal F– anions into 1D [GaF3(IO3)]− anionic chains. According to the experimental characterization and theoretical calculations, both of them exhibit wide bandgaps (4.24 and 4.61 eV), short absorption edges (242 and 216 nm), and large birefringence (Δncal = 0.329 @1064 nm and Δncal = 0.174 @1064 nm for ZrF2(IO3)2 and RbGaF3(IO3), respectively), indicating that they can be candidates as UV birefringent materials.