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

Download

index.pdf

Date

2002-01-01

Author

Hasanlı, Nızamı
Ozkan, H
Kocabas, C

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

54
views

0
downloads

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.

Subject Keywords

Mechanical Engineering, General Materials Science, Mechanics of Materials, Condensed Matter Physics

URI

https://hdl.handle.net/11511/34950

Journal

MATERIALS RESEARCH BULLETIN

DOI

https://doi.org/10.1016/s0025-5408(01)00810-8

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Anharmonicity in GaTe layered crystals Aydinli, A; Hasanlı, Nızamı; Uka, A; Efeoglu, H (Wiley, 2002-01-01) The temperature dependencies (10-300 K) of seven Raman-active mode frequencies in layered semiconductor gallium telluride have been measured in the frequency range from 25 to 300 cm(-1). Softening and broadening of the optical phonon lines are observed with increasing temperature. Comparison between the experimental data and theories of the shift of the phonon lines during heating of the crystal showed that the experimental dependencies can be explained by contributions from thermal expansion and lattice an...
Thermally stimulated currents in n-InS single crystals Hasanlı, Nızamı; Yuksek, NS (Elsevier BV, 2003-03-24) Thermally stimulated current measurements are carried out on as-grown n-InS single crystals in the temperature range of 10-125 K. Experimental evidence is found for four trapping centers present in InS. They are located at 20, 35, 60 and 130 meV. The trap parameters have been determined by various methods of analysis, and they agree well with each other.
Terahertz Resonances in the Dielectric Response Due to Second Order Phonons in a GaSe Crystal Yu, Baolong L; Altan, Hakan; Zeng, Fanang; Kartazayev, Vladimir; Alfano, Robert R; Mandal, Krishna C (2006-09-12) The dielectric function and momentum relaxation time of carriers for a single-crystal GaSe were investigated using terahertz time-domain spectroscopy over the frequency range from 0.4 to 2.4 THz. The key parameters determined from THz data using the Drude model are: the plasma frequency ωp = 6.1 ± 0.5 THz, the average momentum relaxation time <τ> = 51 +± 6 fs for electrons. The THz absorption spectrum showed resonance structures attributed to the difference frequency combinations associated with acoustical ...
Electrical conductivity and Hall mobility in p-type TlGaSe2 crystals Qasrawi, AF; Hasanlı, Nızamı (Elsevier BV, 2004-07-02) Systematic dark electrical conductivity and Hall mobility measurements have been carried out in the temperature range of 200-350 K on p-type TlGaSe2 crystals. The analysis of the temperature-dependent electrical conductivity and carrier concentration reveals the extrinsic type of conduction with an acceptor impurity level located at 0.33 eV, and donor and acceptor concentrations of 9.0 x 10(15) and 1.3 x 10(16) cm(-3), respectively. A hole and electron effective masses of 0.520m(0) and 0.325m(0), respective...
Transient and steady state photoelectronic analysis in TlInSe2 crystals QASRAWI, ATEF FAYEZ HASAN; Hasanlı, Nızamı (Elsevier BV, 2011-08-01) The temperature and illumination effects on the transient and steady state photoconductivities of TlInSe2 crystals have been studied. Namely, two recombination centres located at 234 and at 94 meV and one trap center located at 173 meV were determined from the temperature-dependent steady state and transient photoconductivities, respectively. The illumination dependence of photoconductivity indicated the domination of sublinear and supralinear recombination mechanisms above and below 160 K, respectively. Th...

Citation Formats

N. Hasanlı, H. Ozkan, and C. Kocabas, “Temperature-dependent Raman scattering spectra of epsilon-GaSe layered crystal,” MATERIALS RESEARCH BULLETIN, pp. 169–176, 2002, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34950.