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Phonon thermodynamics and elastic behavior of GaAs at high temperatures and pressures

Herriman, Jane E. and Fultz, Brent (2020) Phonon thermodynamics and elastic behavior of GaAs at high temperatures and pressures. Physical Review B, 101 (21). Art. No. 214108. ISSN 2469-9950. https://resolver.caltech.edu/CaltechAUTHORS:20200611-131726422

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Abstract

The phonons of wurtzite and zinc blende GaAs were calculated at simultaneously elevated temperature and pressure, and elastic constants were calculated as functions of pressure. Pressure caused instabilities of shorter-wavelength transverse acoustic modes in both wurtzite and zinc blende GaAs, causing them to fall to zero at 18 and 20 GPa, respectively. The Born stability criteria, which depend on elastic constants and only long wavelength phonons, therefore overestimated the pressure needed to induce instability at 0 K. At elevated temperatures, explicit anharmonicity pushes the onset of instability to higher pressures in both wurtzite and zinc blende GaAs. Phonon linewidth and densities of states data showed that the quasiharmonic approximation failed to account for temperature-induced phonon frequency shifts, and the quasiharmonic approximation became less reliable at elevated pressure. In general, the number of three-phonon processes increased with pressure, thereby increasing the temperature-driven broadening of phonon spectral lineshapes.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1103/physrevb.101.214108DOIArticle
ORCID:
AuthorORCID
Herriman, Jane E.0000-0003-4769-1403
Fultz, Brent0000-0002-6364-8782
Additional Information:© 2020 American Physical Society. Received 4 January 2020; revised manuscript received 12 April 2020; accepted 27 May 2020; published 11 June 2020. Work by J. E. Herriman was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344. Funding via the LLNL Livermore Graduate Scholar Program and Livermore Computing resources and support made this work possible. Effort by B.F. was supported by DOE Office of Science, BES, under Contract No. DE-FG02-03ER46055. Additional support was provided by the Capital-DOE Alliance Center, funded by the US Department of Energy through the Stewardship Sciences Academic Alliance Program. The author thanks the Quantum Simulations Group at LLNL, especially Babak Sadigh, for useful discussions. Additionally the author thanks Olle Hellman and Nina Shulumba for support of TDEP and its users.
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-AC52-07NA27344
Department of Energy (DOE)DE-FG02-03ER46055
Issue or Number:21
Record Number:CaltechAUTHORS:20200611-131726422
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20200611-131726422
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:103857
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:11 Jun 2020 20:24
Last Modified:11 Jun 2020 20:24

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