Crystal growth, crystal structure, vibrational spectroscopy, linear and nonlinear optical properties of guanidinium phosphates

Of the three guanidinium phosphates GuH(2)PO(4) (space group P2(1)/c), Gu(2)HPO(4) center dot H2O (space group P (4) over bar2(1) c) and Gu(3)PO(4)center dot H2O (space group Cc) crystal structures and a vibrational spectroscopy study are presented. Large single crystals of GuH(2)PO(4) and Gu(2)HPO(4)center dot H2O are grown. Refractive indices and their dispersion in the wavelength range 365 nm - 1083 nm are determined and used for the analysis of phase matching conditions for collinear SHG in the case of the non-centrosymmetric crystals of Gu(2)HPO(4)center dot H2O. The crystals are not phase-matchable within their transmission range. Both independent components of the SHG tensor of Gu(2)HPO(4) center dot H2O, determined by the Maker fringe method, are given, with d(14) = 0.23 pm/V and d(36) = 0.22 pm/V. In addition, the thermal stability and the anisotropy of thermal expansion of GuH(2)PO(4) and Gu(2)HPO(4) center dot H2O is reported. (C) 2017 Elsevier B.V. All rights reserved.