Hg2Br3I: a new mixed halide nonlinear optical material in the infrared region

A new mixed halide, Hg2Br3I, has been synthesized in solution. It crystallizes in the noncentrosymmetric orthorhombic space group Cmc21 (no. 36). In its single crystal, the molecules are arranged in a shuttle-like mode. Its powders show a phase-matchable second harmonic generation (SHG) response of approximately 0.7 times as strong as that of KTiOPO4 (KTP). It also exhibits a wide transparent range (from 0.45 to 38 μm) and a good thermal stability. These results indicate that Hg2Br3I is a promising candidate for NLO materials in the IR region.