Regensburg 2002 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 38: Poster 2

HL 38.49: Poster

Donnerstag, 14. März 2002, 16:30–19:00, Poster A

Bond lengths in Cd_1−xZn_xTe beyond linear laws — •Vasil Koteski, Heinz Haas, Nenad Ivanovic, Elizabeta Holub-Krappe, and Heinz-Eberhard Mahnke — Hahn-Meitner-Institut Berlin, 14109 Berlin

We have investigated the development of local bond lengths with composition in the mixed system Cd_1−xZn_xTe measuring the K-edge absorption (EXAFS). Using all three constituent atoms as central absorbing atom, the local bond strength is found to dominate over the averaging of the bulk (virtual crystal approximation or Vegard’s law). The local bond lengths deviate only slightly from their natural values determined in the pure binary components ZnTe and CdTe. The deviations are significantly less than a quarter of the difference of the lengths in the binary systems as predicted by a simple radial force constant model. Complementing our experimental work we have calculated the local bond lengths within the framework of the density functional theory using the WIEN97 code and obtained good agreement with our experimental results.