Series of Crystals with Giant Optical Anisotropy: A Targeted Strategic Research.

The main commercially used birefringent oxides α-BaB O and YVO have the birefringences of 0.12 and 0.22.

LiBaGaQ (Q = S, Se): Noncentrosymmetric Metal Chalcogenides with a Cesium Chloride Topological Structure Displaying a Remarkable Laser Damage Threshold.

The exploration of novel infrared nonlinear optical (IR NLO) materials with large second-harmonic generation (SHG) responses and wide band gaps has become very imperative recently. Herein we reported two noncentrosymmetric compounds, LiBaGaQ (Q = S, Se), crystallizing in space group 42 (No. 114), which feature 3D frameworks built by a basic [GaQ] windmill cluster and LiQ tetrahedra in a cesium chloride topological structure.

ZnIOF: Zinc Iodate Fluoride with Large Birefringence and Wide Band Gap.

The first zinc iodate fluoride, ZnIOF, was synthesized by the Zn cation, the IO group, and fluorine ion, where Zn is coordinated by O atoms from iodate and F atoms to form the ZnOF polyhedron. It has outstanding optical characteristics, including large birefringence (Δ = 0.219 at 546 nm), wide band gap ( = 4.

Ba(BOF(OH)) with well-ordered OH/F anions and a unique BOF(OH) dimer.

In minerals and artificial crystals, the OH and F groups often coexist and have a high probability of disordered structure. The OH/F position cannot be determined accurately in the crystal structure only by the direct X-ray diffraction method because of the poor contrast between O and F and the weak diffractivity of hydrogen atoms. In this work, a new fluorooxoborate Ba[B2OF3(OH)2]2, with a size of up to 12 × 4 × 3 mm3, has been synthesized successfully by a facile hydrothermal reaction.