Coupling between acoustic and soft transverse optical phonons leads to negative thermal expansion of GeTe near the ferroelectric phase transition

Simple item page
dc.contributor.authorDangic, Dorde
dc.contributor.authorMurphy, Aoife R.
dc.contributor.authorMurray, Éamonn D.
dc.contributor.authorFahy, Stephen B.
dc.contributor.authorSavić, Ivana
dc.contributor.funderScience Foundation Irelanden
dc.date.accessioned2019-08-26T13:32:56Z
dc.date.available2019-08-26T13:32:56Z
dc.date.issued2018-06-26
dc.date.updated2019-08-26T13:25:11Z
dc.description.abstractGeTe is a well-known ferroelectric and thermoelectric material that undergoes a structural phase transition from a rhombohedral to the rocksalt structure at ∼600 – 700 K. We present a first-principles approach to calculate the thermal expansion of GeTe in the rhombohedral phase up to the Curie temperature. We find the minimum of the Helmholtz free energy with respect to the structural parameters, including the internal atomic displacement, in a manner similar to the traditional Grüneisen theory, explicitly accounting for the variation of the static elastic energy with respect to all structural parameters. We obtain the temperature dependence of the structural parameters of rhombohedral GeTe in very good agreement with experiments. In particular, we correctly reproduce a negative volumetric thermal expansion of GeTe near the phase transition. We show that the negative thermal expansion is induced by the coupling between acoustic and soft transverse optical phonons, which is also responsible for the low lattice thermal conductivity of GeTe.en
dc.description.statusPeer revieweden
dc.description.versionPublished Versionen
dc.format.mimetypeapplication/pdfen
dc.identifier.articleid224106en
dc.identifier.citationDangić, Đ., Murphy, A. R., Murray, É. D., Fahy, S. and Savić, I. (2018) 'Coupling between acoustic and soft transverse optical phonons leads to negative thermal expansion of GeTe near the ferroelectric phase transition', Physical Review B, 97(22), 224106 (10 pp). doi: 10.1103/PhysRevB.97.224106en
dc.identifier.doi10.1103/PhysRevB.97.224106en
dc.identifier.endpage10en
dc.identifier.issn2469-9950
dc.identifier.issued22en
dc.identifier.journaltitlePhysical Review Ben
dc.identifier.startpage1en
dc.identifier.urihttps://hdl.handle.net/10468/8390
dc.identifier.volume97en
dc.language.isoenen
dc.publisherAmerican Physical Societyen
dc.relation.projectinfo:eu-repo/grantAgreement/SFI/SFI Investigator Programme/15/IA/3160/IE/Thermoelectric efficiency of IV-VI and V2-VI3 materials driven near phase transitions/en
dc.relation.projectinfo:eu-repo/grantAgreement/SFI/SFI Infrastructural Support/08/HEC/I1450/IE/Establishment of ICHEC as a National Facility for High-End Computing/en
dc.relation.urihttps://link.aps.org/doi/10.1103/PhysRevB.97.224106
dc.rights© 2018 American Physical Societyen
dc.subjectFerroelectricityen
dc.subjectPhase transitionsen
dc.subjectThermal expansionen
dc.subjectThermoelectric effectsen
dc.subjectFerroelectricsen
dc.subjectThermoelectric systemsen
dc.subjectDensity functional calculationsen
dc.titleCoupling between acoustic and soft transverse optical phonons leads to negative thermal expansion of GeTe near the ferroelectric phase transitionen
dc.typeArticle (peer-reviewed)en
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
6529.pdf
Size:
896.05 KB
Format:
Adobe Portable Document Format
Description:
Published version
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
2.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Physics - Journal Articles
Tyndall National Institute - Journal Articles