Nanometer-scale mechanism of phase-change optical recording as revealed by XAFS

A. V. Kolobov; P. Fons; J. Tominaga; A. I. Frenkel; A. L. Ankudinov; T. Uruga

doi:10.1016/j.nimb.2005.12.017

Nanometer-scale mechanism of phase-change optical recording as revealed by XAFS

A. V. Kolobov
, P. Fons
, J. Tominaga
, A. I. Frenkel
, A. L. Ankudinov
, T. Uruga

Materials Science and Engineering

National Institute of Advanced Industrial Science and Technology
University of Washington
Japan Synchrotron Radiation Research Institute

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

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.

Original language	English
Pages (from-to)	69-74
Number of pages	6
Journal	Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume	246
Issue number	1
DOIs	https://doi.org/10.1016/j.nimb.2005.12.017
State	Published - May 2006

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title = "Nanometer-scale mechanism of phase-change optical recording as revealed by XAFS",

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.",

author = "Kolobov, \{A. V.\} and P. Fons and J. Tominaga and Frenkel, \{A. I.\} and Ankudinov, \{A. L.\} and T. Uruga",

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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

Y1 - 2006/5

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.

UR - https://www.scopus.com/pages/publications/33646493344

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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 -

Nanometer-scale mechanism of phase-change optical recording as revealed by XAFS

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