IR absorption spectroscopy of water in CsLiB6O10 crystals

Abstract

AbstractPolarized absorption spectra of CsLiB 6 O 10 crystals have been measured between )186 and 25 C in the 1500–7500cm 1 wavenumber range. A series of absorption bands have been observed with intensities depending on the thermalhistory of the crystals. Three of them have been assigned as the fundamental H–O–H bending mode (d ¼ 1650 cm 1 ),and symmetric and asymmetric OH stretching modes of the bound H 2 O molecule (m s ¼ 3413 cm 1 and m a ¼ 3581 cm 1 ,respectively). Additional features in the 3800–4400, 4700–5300 and 6500–7100 cm 1 ranges have been interpreted asovertones and combinations of the fundamental H 2 O vibrations. The above assignments have been verified by detectingthe isotopic replica of the bands in a crystal treated in D 2 O vapour atmosphere. The possible sites for the H 2 O moleculein the lattice have been deduced from polarization angle dependence measurements. 2003 Elsevier B.V. All rights reserved. PACS: 42.70.Mp; 61.72.)y; 78.30.HvKeywords: FTIR spectroscopy; H