Crystal growth, thermal expansion, pyroelectricity and vibrational spectroscopy of barium antimony tartrate, Ba[Sb-2((+)C4H2O6)(2)]center dot 3H(2)O

The tetragonal polar barium antimony tartrate trihydrate, Ba[Sb-2((+)C4H2O6)(2)]center dot 3H(2)O, was grown to large single crystals of optical quality and several cm dimensions. A vibrational spectroscopy study, thermal expansion measurements and a determination of the pyroelectric properties were performed and possibilities for phase matching for second harmonic generation (SHG) were analysed. The crystals show a remarkable high pyroelectric coefficient, a moderate anisotropy of thermal expansion and allow for type I and type II phase matching for collinear SHG. A redetermination of the crystal structure of Ba[Sb-2((+)C4H2O6)(2)]center dot 3H(2)O at 150 K is given in addition, together with the vibrational spectra and crystal structures of two new related compounds, Ba [As-2((+)C4H2O6)(2)]center dot 3H(2)O and Ba[Sb-2((+)C4H2O6)(2)]center dot 4H(2)O, determined at the same temperature

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

Cocrystals of 2-Aminopyrimidine with Boric Acid-Crystal Engineering of a Novel Nonlinear Optically (NLO) Active Crystal

Crystal engineering of novel materials for nonlinear optics (NLO) based on 2-aminopyrimidine yielded two molecular cocrystals with boric acid-trigonal (P3(2)21 space group) 2-aminopyrimidine-boric acid (3/2) and monoclinic (C2/c space group) 2-aminopyrimidine-boric acid (1/2). In addition to crystal structure determination by single crystal X-ray diffraction, the cocrystals were characterized by powder X-ray diffraction and vibrational spectroscopy (FTIR and FT Raman). Large single crystals of the non-centrosymmetric cocrystal 2-aminopyrimidine-boric acid (3/2) were grown to study the optical properties and determine the second harmonic generation (SHG) efficiency (using 800 nm fundamental laser line) of powder samples

Linear and nonlinear optical properties, pyroelectricity and vibrational spectroscopy of polar guanidinium hydrogen phosphite, GuH(2)PO(3) , and hydrogen selenite, GuHSeO(3)

For the non-centrosymmetric guanidinium compounds GuH(2)PO(3) and GuHSeO(3) with polar symmetry P2(1) a fundamental characterization as optical materials is given, including X-ray crystal structure analysis and a vibrational spectroscopy (Raman and IR) study. In addition, for both polar crystals the pyroelectric coefficients and their temperature dependence are evaluated. Using large single crystals grown from aqueous solution, refractive indices and their dispersion in the wavelength range 435-1083 nm are determined by the prism method. From the data phase matching conditions for collinear second harmonic generation (SHG) are analysed. Both crystals allow the realization of phase matching for SHG of both, type I and type II processes. Quantification of SHG properties was performed for both powdered salts and GuH(2)PO(3) single crystals. The measurements of the pyroelectric coefficients in the temperature range 100-340 K show pronounced pyroelectricity but no indication for ferroelectric behaviour of the two crystals