Transverse effective charge and its pressure dependence in GaN single crystals
1999; American Physical Society; Volume: 60; Issue: 3 Linguagem: Inglês
10.1103/physrevb.60.1480
ISSN1095-3795
AutoresP. Perlin, T. Suski, Joel W. Ager, G. Conti, A. Polian, N. E. Christensen, I. Gorczyca, I. Grzegory, E. R. Weber, E. E. Häller,
Tópico(s)Metal and Thin Film Mechanics
ResumoThe pressure dependence of the ${A}_{1}(\mathrm{TO})$ and ${A}_{1}(\mathrm{LO})\mathrm{}$ phonon modes of bulk, single crystals of wurtzite GaN has been measured by Raman scattering in a diamond-anvil cell up to 40 GPa. The measured phonon frequencies have been used to determine the LO and TO phonon-mode Gr\"uneisen parameters and also the value of effective transverse charge ${e}_{T}^{*}=2.6$ and its pressure derivative ${\mathrm{de}}_{T}^{*}/dP=\ensuremath{-}2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3} {\mathrm{GPa}}^{\ensuremath{-}1}$. The experimentally obtained values are compared with results of calculations by means of tight-binding formalism combined with ab initio linear muffin-tin orbital calculations.
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