First-principles study of pyroelectricity in GaN and ZnO

First-principles calculations are made for the primary pyroelectric coefficients of wurtzite GaN and ZnO. The pyroelectricity is attributed to the quasiharmonic thermal shifts of internal strains (internal displacements of cations and anions carrying their Born effective charges). The primary (zero-...

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Bibliographic Details
Published inarXiv.org
Main Authors Liu, Jian, Fernández-Serra, Maria V, Allen, Philip B
Format Paper Journal Article
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 02.03.2016
Subjects
First principles
Physics - Materials Science
Pyroelectricity
Wurtzite
Zinc oxide
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Summary:First-principles calculations are made for the primary pyroelectric coefficients of wurtzite GaN and ZnO. The pyroelectricity is attributed to the quasiharmonic thermal shifts of internal strains (internal displacements of cations and anions carrying their Born effective charges). The primary (zero-external-strain) pyroelectricity dominates at low temperatures, while the secondary pyroelectricity (the correction from external thermal strains) becomes comparable with the primary pyroelectricity at high temperatures. Contributions from the acoustic and the optical phonon modes to the primary pyroelectric coefficient are only moderately well described by the corresponding Debye function and Einstein function respectively.
ISSN:2331-8422
DOI:10.48550/arxiv.1603.00657