Low-frequency inelastic light scattering from chalcogenide glasses and alloys

Journal Article · Mon Aug 15 00:00:00 EDT 1977 · Phys. Rev., B; (United States)

DOI:https://doi.org/10.1103/PhysRevB.16.1655· OSTI ID:7215040

Nemanich, R J

Polarized low-frequency Raman and Brillouin spectra of the chalcogenide glasses As/sub 2/S/sub 3/, GeS/sub 2/, GeSe/sub 2/, and As/sub 2/Se/sub 3/ and the glass alloy system (As/sub 2/S/sub 3/)/sub 1-x/(GeS/sub 2/)/sub x/ have been measured using the near infrared 7525 or 7993 A lines of a krypton laser. The low-temperature T approx. 10 K spectra of the four binary glasses indicate that the Raman coupling constant exhibits an ..omega../sup 2/ frequency dependence in the limit ..omega.. ..-->.. 0. In addition it is demonstrated that the spectral distribution of the low-frequency low-temperature Raman coupling constant can be described by a model proposed by Martin and Brenig. By fitting the predicted spectra of the model to the experimentally obtained spectra, the structural correlation ranges of the glasses have been determined. It is found that the structural correlation ranges of the As/sub 2/S/sub 3/ and As/sub 2/Se/sub 3/ glasses are 6.5 +- 1 A, while those of the GeS/sub 2/ and GeSe/sub 2/ glasses are 8.5 +- 1 A. These results are compared with values of structural correlations obtained from x-ray diffraction spectra and optic-mode Raman spectra. The depolarization spectra predicted from the Martin and Brenig model are found to deviate significantly from the observed low-frequency depolarization spectra of the chalcogenide glasses. At higher temperatures the low-frequency Raman spectra of all samples exhibit a feature apparently centered at 0 frequency shift which cannot be described by the model of Martin and Brenig. A similar feature termed the light scattering excess has been reported for the low-frequency Raman spectrum of fused silica. The composition dependence of both the structural correlation range and the light-scattering excess is presented for the alloy system of (As/sub 2/S/sub 3/)/sub 1-x/(GeS/sub 2/)/sub x/.

• Research Organization: Department of Physics, James Franck Institute, University of Chicago, Chicago, Illinois 60637
• OSTI ID: 7215040
• Journal Information: Phys. Rev., B; (United States), Vol. 16:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARSENIC SELENIDES
BRILLOUIN EFFECT
RAMAN SPECTRA
ARSENIC SULFIDES
GERMANIUM SELENIDES
GERMANIUM SULFIDES
GLASS
CHALCOGENIDES
DEPOLARIZATION
NEAR INFRARED RADIATION
ULTRALOW TEMPERATURE
ARSENIC COMPOUNDS
COHERENT SCATTERING
ELECTROMAGNETIC RADIATION
GERMANIUM COMPOUNDS
INFRARED RADIATION
RADIATIONS
SCATTERING
SELENIDES
SELENIUM COMPOUNDS
SPECTRA
SULFIDES
SULFUR COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties