Coexistence of tetrahedral and octahedral-like sites in amorphous phase change materials

2007/08/31 by S. Caravati, M. Bernasconi, T. D. Kuehne +2 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.dis-nn

paper · pdf · doi:10.1063/1.2801626

published as Applied Physics Letters 91, 171906 (2007) · 6 pages, 10 figures including supplementary material

arxiv created 2008/04/01 · arxiv updated 2009/12/01

Abstract

Chalcogenide alloys are materials of interest for optical recording and non-volatile memories. We perform ab-initio molecular dynamics simulations aiming at shading light onto the structure of amorphous Ge2Sb2Te5 (GST), the prototypical material in this class. First principles simulations show that amorphous GST obtained by quenching from the liquid phase displays two types of short range order. One third of Ge atoms are in a tetrahedral environment while the remaining Ge, Sb and Te atoms display a defective octahedral environment, reminiscent of cubic crystalline GST.

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