A new ultraviolet (UV) nonlinear optical (NLO) crystal Sr4B 10O18(OH)2·2H2O has been synthesized using the hydrothermal method. It crystallizes in the triclinic space group P1 (no. 1) with lattice constants a = 6.4991(6) A˚, b = 6.5059(6) A˚, c = 11.3175(11) A˚, α = 88.458(6)°, β = 86.019(5)°, γ = 61.351(5)°, Z = 1. The fundamental building block of the structure is a [B10O23]16- unit which consists of two stereo-isomeric configurations of [B5O 12]9- groups. The structure exhibits a ∞[B10O18]6- three dimensional network with 9-membered tunnels along the b-axis where the Sr cation, OH anion and H2O molecule are located. Powder second harmonic generation (SHG) measurements indicate that Sr4B10O18(OH) 2·2H2O is type-I phase-matchable and displays a SHG response of about 2 × KH2PO4. The UV-Vis-NIR diffuse reflectance spectrum shows that its cutoff edge is lower than 190 nm. Density functional theory (DFT) calculations on electronic structures and SHG coefficients confirm the experimental results.
Chinese Acad Sci, Key Lab Funct Mat & Devices Special Environm, Xinjiang Key Lab Elect Informat Mat & Devices, Xinjiang Tech Inst Phys & Chem, Urumqi 830011, Peoples R China；Xinjiang Univ, Coll Chem & Chem Engn, Urumqi 830046, Peoples R China；Univ Chinese Acad Sci, Beijing 100049, Peoples R China
Fangyuan Zhang,Qun Jing,Fangfang Zhang,et al. Sr4B10O18(OH)(2)center dot 2H(2)O: a new UV nonlinear optical material with a [B10O23](16-) building block[J]. Journal of Materials Chemistry C,2014,2(4):667-674.