Struzhkin VV, Mao HK, Lin JF, Hemley RJ, Tse JS, Ma Y, Hu MY, Chow P, Kao CC. Valence band x-ray emission spectra of compressed germanium.
PHYSICAL REVIEW LETTERS 2006;
96:137402. [PMID:
16712032 DOI:
10.1103/physrevlett.96.137402]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Revised: 03/03/2006] [Indexed: 05/09/2023]
Abstract
We report measurements of the valence band width in compressed Ge determined from x-ray emission spectra below the Ge K edge. The width of the valence band does not show any pressure dependence in the semiconducting diamond-type structure of Ge below 10 GPa. On the other hand, in the metallic beta-Sn phase above 10 GPa the valence band width increases under compression. Density-functional calculations show an increasing valence band width under compression both in the semiconducting phase (contrary to experiment) and in the metallic beta-Sn phase of Ge (in agreement with observed pressure-induced broadening). The pressure-independent valence band width in the semiconducting phase of Ge appears to require theoretical advances beyond the density-functional theory or the GW approximation.
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