Vibrational spectra of WO3•nH2O and WO3 polymorphs

Vibrational spectra of polycrystalline WO3 hydrates and polymorphs were measured and analyzed. The effect of sampling techniques on IR spectra has been demonstrated. The phase transition into triclinic polymorph (C-2h(2) --> C-i(1)) has been revealed for the sample of monoclinic WO3 prepared as KBr pellet. Using the deuteration method in situ has shown that cubic WO3 is non-stoichiometric oxide stabilized by residual OH groups of WO3 center dot H2O precursor. (C) 2010 Elsevier B.V. All rights reserved.