IR absorption spectroscopy of water in CsLiB6O10 crystals

Polarized absorption spectra of CsLiB6O10 crystals have been measured between -186 and 25 degreesC in the 1500-7500 cm(-1) wavenumber range. A series of absorption bands have been observed with intensities depending on the thermal history of the crystals. Three of them have been assigned as the fundamental H-O-H bending mode (delta = 1650 cm(-1)), and symmetric and asymmetric OH stretching modes of the bound H2O molecule (v(s) = 3413 cm(-1) and v(a) = 3581 cm(-1), respectively). Additional features in the 3800-4400, 4700-5300 and 6500-7100 cm(-1) ranges have been interpreted as overtones and combinations of the fundamental H2O vibrations. The above assignments have been verified by detecting the isotopic replica of the bands in a crystal treated in D2O vapour atmosphere. The possible sites for the H2O molecule in the lattice have been deduced from polarization angle dependence measurements. (C) 2003 Elsevier B.V. All rights reserved.