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Raman scattering from the effective soft mode in lead germanate crystal
Author(s) -
Gorelik V.S.,
Pyatyshev A.Yu.
Publication year - 2020
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.5854
Subject(s) - raman spectroscopy , raman scattering , soft modes , germanate , opalescence , wavenumber , phase transition , x ray raman scattering , materials science , coherent anti stokes raman spectroscopy , molecular physics , phase (matter) , optics , chemistry , condensed matter physics , ferroelectricity , analytical chemistry (journal) , physics , optoelectronics , organic chemistry , doping , chromatography , dielectric
The Raman opalescence of an effective soft mode in crystalline lead germanate is investigated. Recording of Raman scattering intensity was in the x (zz)y geometry corresponding to the soft mode, responsible for ferroelectric phase transition point at 451 K. The Raman spectra were measured at fixed temperatures T ( I ( ω ′, T ); T = const) and also at fixed wavenumbers ω ′ of Raman spectrometer ( I ( ω ′, T ); ω ′ = ω 0 – Ω = const) with slow temperature changing. The strong increase of Raman scattering intensity (Raman opalescence) has been observed at temperatures of phase transition region. The appearance of central peak scattering is attributed to the strong interaction of the effective soft mode with a low‐wavenumber nonfundamental oscillator.