Premium
Phonon calculation on olivine‐like LiMPO 4 (M = Ni, Co, Fe) and Raman scattering of the iron‐containing compound
Author(s) -
Paraguassu W.,
Freire P. T. C.,
Lemos V.,
Lala S. M.,
Montoro L. A.,
Rosolen J. M.
Publication year - 2005
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1278
Subject(s) - raman spectroscopy , isostructural , raman scattering , phonon , wavenumber , chemistry , olivine , analytical chemistry (journal) , transition metal , crystal structure , crystallography , materials science , molecular physics , mineralogy , physics , condensed matter physics , optics , biochemistry , chromatography , catalysis
The phonon properties of the lithium transition metal phosphates LiMPO 4 (M = Ni, Co, Fe) with the olivine structure were studied using a computational simulation. The calculation employs a normal coordinate analysis based on the Wilson's FG matrix method. The method applied to LiNiPO 4 allowed for the fitting of a set of stretching force constants and angle bond strengths that resulted in Raman wavenumbers comparing with experiments within a 5% average deviation. This set was assumed fixed for the isostructural Co‐containing and Fe‐containing compounds, as a first approximation. The calculated LiCoPO 4 Raman wavenumbers also compared well with experimental values (average deviation 9%). Using this procedure, the 36 Raman wavenumbers of LiFePO 4 were predicted and assigned to vibrational motions and symmetry species of the crystal group. LiFePO 4 unpolarized Raman data agree very well with the predicted values. Copyright © 2004 John Wiley & Sons, Ltd.