title: Explorations of new second-order nonlinear optical materials in the ternary rubidium iodate system: noncentrosymmetric β-RbIO3(HIO3)2 and centrosymmetric Rb3(IO3)3(I2O5)(HIO3)4(H2O).
abstract: Two new rubidium iodates, namely, β-RbIO3(HIO3)2 (1, P1) and Rb3(IO3)3(I2O5)(HIO3)4(H2O) (2, P21/c), have been synthesized by hydrothermal reaction and their structures determined by single-crystal X-ray diffraction. Compound 1 exhibits IO3(-) anions and neutral HIO3 molecules which are interconnected by Rb(+) cations into three-dimensional structure. Compound 2 features a two-dimensional layered structure formed by IO3(-) anions and neutral HIO3 and dimeric I2O5 molecules interconnected by Rb(+) cations. Large bulk crystal of 1 with dimensions of several millimeters has been grown. UV-vis-NIR transmission spectroscopy measurements on a slab of a polished crystal of 1 indicated that the crystal possesses a short-wavelength absorption edge onset at 305 nm. Powder second-harmonic generation (SHG) measurements on sieved crystals revealed that 1 is a type I phase-matchable material with an SHG response about 1.5 times that of KH2PO4. The Vickers hardness of crystal of 1 has been measured to be 110 HV, and the laser-induced damage threshold has been confirmed to be 18.26 J/cm(2) with a laser wavelength of 1064 nm and a pulse duration of 10 ns. Moreover, thermal stabilities and vibrational spectra for both 1 and 2 have also been studied.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou 350002, People's Republic of China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Xu
authors.forename: Bing-Ping
authors.initials: BP
authors.lastname: Yang
authors.forename: Chao
authors.initials: C
authors.lastname: Huang
authors.forename: Jiang-Gao
authors.initials: JG
authors.lastname: Mao