Explorations of New SHG Materials in Mercury Iodate Sulfate System.

ABSTRACT

Through systematic experiments, two novel mercury iodate sulfates, namely, Hg2 (IO3 )2 (SO4 )(H2 O) and Hg2 (IO3 )2 (SO4 ) were obtained. They crystallize in monoclinic space group C2 and C2/c, respectively. Hg2 (IO3 )2 (SO4 )(H2 O) exhibits the [Hg(IO3 )]+ polar cationic layer inherited from Hg(IO3 )2 and the three-dimensional (3D) framework inherited from HgSO4 . This enables Hg2 (IO3 )2 (SO4 )(H2 O) to generate a strong second harmonic generation (SHG) response of 6 times that of KH2 PO4 (KDP). The structure of Hg2 (IO3 )2 (SO4 ) is very similar to that of Hg2 (IO3 )2 (SO4 )(H2 O), and they can be transformed into each other. Hg2 (IO3 )2 (SO4 )(H2 O) shows a large optical band gap of 3.98 eV and a high dehydration temperature of 250 °C. This study indicates that by reasonable design, the introduction of multiple functional groups into a compound may combine their advantages to achieve good overall optical performance.