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Structural phase transitions in loparite‐(Ce): evidences from Raman light scattering
Author(s) -
Popova E. A.,
Yakovenchuk V. N.,
Lushnikov S. G.,
Krivovichev S. V.
Publication year - 2015
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.4587
Subject(s) - raman spectroscopy , wavenumber , raman scattering , ferroelectricity , phase transition , anisotropy , x ray raman scattering , phase (matter) , coherent anti stokes raman spectroscopy , softening , condensed matter physics , materials science , soft modes , chemistry , atmospheric temperature range , molecular physics , nuclear magnetic resonance , optics , physics , thermodynamics , dielectric , optoelectronics , organic chemistry , composite material
Raman spectroscopic studies of loparite‐(Ce), a mineral of the perovskite family, are presented. Polarized Raman spectra were obtained in the temperature range of 50–300 K. As analysis of the behavior of Raman modes showed, the temperature dependences of wavenumber, damping and intensity of the optical modes exhibited anomalies near 220 and 150 K. Softening of the low‐wavenumber modes observed in the vicinity of 150 K is interpreted as an evidence of a ferroelectric phase transition. An anisotropic quasielastic light scattering in the low‐wavenumber region of the Raman spectra was observed from 300 to 150 K. As the data suggest, loparite‐(Ce) has two structural phase transitions, one of which (at 150 K) is a ferroelectric transition of the order–disorder type. Copyright © 2014 John Wiley & Sons, Ltd.