Premium
Anharmonic Line Shift and Linewidth of the Raman Modes in GaS 0.75 Se 0.25 Layered Crystals
Author(s) -
Gasanly N.M.,
Pala R.
Publication year - 2002
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200211)234:2<665::aid-pssb665>3.0.co;2-2
Subject(s) - anharmonicity , phonon , laser linewidth , raman spectroscopy , condensed matter physics , atmospheric temperature range , softening , lattice (music) , thermal expansion , coupling (piping) , materials science , line (geometry) , molecular vibration , chemistry , molecular physics , optics , physics , thermodynamics , laser , geometry , mathematics , acoustics , metallurgy , composite material
The frequencies and linewidths of five Raman‐active modes in a GaS 0.75 Se 0.25 layered crystal have been measured in the 10–300 K temperature range and in the 10–380 cm —1 frequency region. We observed softening and broadening of the optical phonon lines with increasing temperature. The analysis of the experimental data showed that the temperature dependencies of frequencies and linewidths are well described by considering the contributions from thermal expansion and lattice anharmonicity. The purely anharmonic contribution (phonon–phonon coupling) is found to be due to three‐phonon processes.