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

被引:351
作者
Caravati, S.
Bernasconi, M.
K hne, T. D.
Krack, M.
Parrinello, M.
机构
[1] Univ Milano Bicocca, Dipartimento Sci Mat, I-20125 Milan, Italy
[2] Swiss Fed Inst Technol, Dept Chem & Appl Biosci, CH-6900 Lugano, Switzerland
关键词
D O I
10.1063/1.2801626
中图分类号
O59 [应用物理学];
学科分类号
摘要
Chalcogenide alloys are materials of interest for optical recording and nonvolatile 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. (C) 2007 American Institute of Physics.
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