Temperature-dependent Raman scattering spectra of epsilon-GaSe layered crystal

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Gasanly N., Aydinli A., Ozkan H., Kocabas C.

MATERIALS RESEARCH BULLETIN, cilt.37, sa.1, ss.169-176, 2002 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 37 Sayı: 1
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1016/s0025-5408(01)00810-8
  • Dergi Adı: MATERIALS RESEARCH BULLETIN
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.169-176
  • Anahtar Kelimeler: chalcogenides, semiconductors, Raman spectroscopy, optical properties, LATTICE-VIBRATIONS, OPTICAL PHONONS, ENERGY
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The temperature dependencies (15-300 K) of seven Raman-active mode frequencies and linewidths in layered gallium selenide have been measured in the frequency range from 10 to 320 cm(-1). We observed softening and broadening of the optical phonon lines with increasing temperature. Comparison between the experimental data and theories of the shift and broadening of the intralayer phonon lines during heating of the crystal showed that the experimental dependencies can be explained by the contributions from thermal expansion., lattice anharmonicity and crystal disorder. The pure-temperature contribution (phonon-phonon coupling) is due to three-phonon processes. Moreover, it was established that the effect of crystal disorder on the linewidth broadening of TO mode is stronger than that of LO mode. (C) 2002 Elsevier Science Ltd. All rights reserved.