A Series of Mixed-Metal Germanium Iodates as Second-Order Nonlinear Optical Materials

Mao, Fei-Fei,Hu, Chun-Li,Chen, Jin,Mao, Jiang-Gao

, p. 2443 - 2452 (2018)

A series of new compounds in the A/Ae-Ge4+-IO3 system, namely, A2Ge(IO3)6 (A = Li, Na, Rb, or Cs) and BaGe(IO3)6(H2O), have been obtained by introducing GeO6 octahedra into a ternary metal iodate system. The structures of all five new compounds feature a zero-dimensional [Ge(IO3)6]2- anion composed of a GeO6 octahedron connecting with six IO3 groups, the alkali or alkali-earth cations acting as spacers between these anions and maintaining charge balance. Interestingly, the isomeric Li2Ge(IO3)6 and Na2Ge(IO3)6 are noncentrosymmetric (NCS), whereas the isostructural Rb2Ge(IO3)6 and Cs2Ge(IO3)6 are centrosymmetric. BaGe(IO3)6(H2O) is the first NCS alkali-earth germanium iodate reported. Powder second-harmonic generation (SHG) measurements show that Li2Ge(IO3)6, Na2Ge(IO3)6, and BaGe(IO3)6(H2O) crystals are phase-matchable and display very large SHG signals that are approximately 32, 15, and 12 times that of KH2PO4, respectively, under 1064 nm radiation and 2, 0.8, and 0.8 times that of KTiOPO4, respectively, under 2.05 mm laser radiation. The compounds show high thermal stability and a large laser damage threshold, indicating their potential applications as nonlinear optical (NLO) materials in visible and infrared spectral regions. Measurement of optical properties, thermal analysis, and theoretical calculations of the SHG origin have been performed. Our studies indicate that introducing non-second-order Jahn-Teller-distortive MO6 octahedra into metal iodate systems can also lead to good mixed-metal iodate NLO materials.

Barker, T. V.

, p. 15 - 15 (1908)

Characterization of Molecular Alkali Metal Iodates by Mass Spectrometry and Matrix Isolation IR Spectroscopy

Biggs, Karen R.,Gomme, Robin A.,Graham, John T.,Ogden, J. Steven

, p. 9738 - 9741 (1992)

Samples of the solids MIO3 (M = Li, Na, K, Rb, Cs) have been vaporized in vacuo and the ternary products characterized by mass spectrometry, and by infrared spectroscopy in low-temperature nitrogen, oxygen and argon matrices.The molecular species KiO3, RbIO3, and CsIO3 have been identified for the first time and their IR spectra shown to be consistent with overall C3v symmetry involving tridentate coordination.This conclusion is further confirmed, in the case of CsIO3 isolated in argon, by a detailed analysis of (18)O isotope patterns.In contrast, samples of LiIO3 and NaIO3 appeared to undergo decomposition to the iodide and oxygen.

A series of new alkali metal indium iodates with isolated or extended anions

Yang, Bing-Ping,Sun, Chuan-Fu,Hu, Chun-Li,Mao, Jiang-Gao

, p. 1055 - 1060 (2011)

Systematic explorations of new phases in the AI-In III-IV-O system by hydrothermal reactions led to five new compounds, namely, AIn(IO3)4 (A = Li, Na), Rb 3In(IO3)6 an