Article,
Temperature-dependent Raman scattering study of K2MoO4
VIBRATIONAL SPECTROSCOPY, (2012)
DOI: 10.1016/j.vibspec.2011.11.015
Abstract
This research reports a temperature-dependent Raman scattering study of
dipotassium molybdate (K2MoO4) in the 18-913 K temperature range. This
study indicates that K2MoO4 crystal exhibits a temperature-induced
first-order phase transition at around 578 K from monoclinic phase to
incommensurate phase. The phase transition is connected with tilting
and/or rotations of the MoO4 tetrahedra that lead to a disorder in the
MoO4 sites. An orthorhombic phase (alpha'-phase) of K2MoO4 was obtained
when the low-temperature monoclinic structure was heated or when
high-temperature hexagonal structure was cooled. A lattice dynamic
calculation was performed by using the classical rigid ion model, in
order to predict both wavenumbers and atomic displacements
(eigenvectors) for the vibrational modes of the monoclinic phase of
K2MoO4 and K2WO4. (C) 2011 Elsevier B.V. All rights reserved.
