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Analysis of Multiphonon Absorption in Corundum
Author(s) -
Billard D.,
Gervais F.,
Piriou B.
Publication year - 1976
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/pssb.2220750111
Subject(s) - anharmonicity , corundum , phonon , renormalization , condensed matter physics , absorption (acoustics) , physics , chemistry , quantum mechanics , optics , mineralogy
The frequency and temperature dependence of the infrared absorption coefficient of corundum over the range 1400 to 2500 cm −1 is analysed with an anharmonic model based on the concept of phonon self‐energy. A renormalization accounts for important effects of thermal expansion and phonon frequency shifts. First, the analysis of the temperature dependence of the data allows to separate the contributions to the absorption of different w‐phonon summation processes ( n = 2 to 5). Results are found to be quite consistent with theoretical predictions. Then each n ‐phonon contribution can be investigated in detail, and it is shown that the use of simple forms for average anharmonic potentials is adequate to explain the frequency dependence of the w‐phonon absorptions. The analysis of the results on the basis of a quite different theoretical model is also discussed.