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Temperature‐ and pressure‐dependent phonon dynamics properties of gallium selenide telluride
Ist Teil von
Journal of Raman spectroscopy, 2022-07, Vol.53 (7), p.1275-1284
Ort / Verlag
Bognor Regis: Wiley Subscription Services, Inc
Erscheinungsjahr
2022
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Understanding the thermodynamic properties of materials is a fundamental issue in physics, and its knowledge is crucial for targeting a specific material for possible applications. In this work, we report a temperature‐ and pressure‐dependent Raman study of bulk GaSe0.5Te0.5 alloy, besides their relevant thermodynamic parameters. Our results show a nonlinear redshift for the
A1g and
E2g vibrational modes as the temperature increases in the temperature range from 10 to 748 K. Such behavior is well described by considering both thermal expansion and phonon–phonon coupling contributions. By combining density functional theory (DFT) calculations and Raman spectroscopy experiments, the anharmonic constants relative to the three‐ and four‐phonon decay processes, mode‐Grüneisen parameters, Debye temperature, thermal expansion coefficient, and bulk modulus were estimated for GaSe0.5Te0.5 alloy. Furthermore, the high‐pressure measurements and DFT calculations, performed in the pressure range from 0 to 26.4 GPa, show a quadratic trend for the
ωA1g and
ωE2g modes as a function of pressure, with the
A1g modes being more compressible than
E2g one, that is,
∂ωA1g∂P>∂ωE2g∂P. No structural phase transition is observed until the maximum pressure reached in the experiment. This study took a step forward in the understanding of mechanical and thermal properties related to GaSe0.5Te0.5 alloy, whose determined parameters are important for designing new applications.
We present a temperature‐ and pressure‐dependent Raman spectroscopy study of bulk GaSe0.5Te0.5 in order to access its thermal and mechanical properties. By combining DFT calculations and Raman spectroscopy experiments, the anharmonic constants relative to the three‐ and four‐phonon decay processes, mode‐Grüneisen parameters, Debye temperature, thermal expansion coefficient, and bulk modulus were estimated.