| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1688064 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2006 | 6 Pages |
Abstract
We demonstrate that the Ge(Sb)–Te bond lengths in crystallized cubic Ge2Sb2Te5 (GST) are significantly lower than the values expected from the previous X-ray diffraction (XRD) analysis. At the same time, the second nearest-neighbour Te–Te distances are in perfect agreement with XRD. We conclude that the structure of GST is a distorted rocksalt structure. Upon amorphization, Ge–Te and Sb–Te bonds get shorter and stronger. This unusual behaviour is due to a switch of Ge atom from an octahedral symmetry position in the crystalline state into a tetrahedral symmetry position in the amorphous state. It is this switching of the Ge atoms that is responsible for the fast and stable media performance.
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Authors
A.V. Kolobov, P. Fons, J. Tominaga, A.I. Frenkel, A.L. Ankudinov, T. Uruga,