TY - JOUR
T1 - Nanometer-scale mechanism of phase-change optical recording as revealed by XAFS
AU - Kolobov, A. V.
AU - Fons, P.
AU - Tominaga, J.
AU - Frenkel, A. I.
AU - Ankudinov, A. L.
AU - Uruga, T.
PY - 2006/5/1
Y1 - 2006/5/1
N2 - 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.
AB - 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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U2 - 10.1016/j.nimb.2005.12.017
DO - 10.1016/j.nimb.2005.12.017
M3 - Article
AN - SCOPUS:33646493344
SN - 0168-583X
VL - 246
SP - 69
EP - 74
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
IS - 1
ER -