Local vs. global order in GeTe-based phase-change alloys
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F12%3A39896017" target="_blank" >RIV/00216275:25310/12:39896017 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Alternative languages
Result language
angličtina
Original language name
Local vs. global order in GeTe-based phase-change alloys
Original language description
In the low temperature GeTe crystalline phase, Ge and Te atoms are sixfold coordinated by each other with subsets of three shorter 2.83 ? and three longer 3.15 ? bonds often described as a Peierl distortion. Based on Bragg-diffraction studies, it was concluded that rhombohedral GeTe undergoes a displacive ferroelectric-paralectric transition with the Curie temperature,Tc, around 705 K transforming to the rocksalt structure (Fm3m). Alloying of GeTe with Sb2Te3 generates vacancies which, together with newSb-Te bonds, gradually decreases the value of the Curie temperature. When Sb2Te3 exceeds 0.137 in (GeTe)x(Sb2Te3)1?x, only the cubic phase can be observed using the Bragg diffraction2. Here, we demonstrate through the combined use of x-ray Bragg diffraction and EXAFS that although the global structure of Ge-Sb-Te undergoes a rhombohedral to rock-salt-like structural transition, locally the material maintains a 3 + 3 bond length splitting configuration at temperatures above Tc, that is,
Czech name
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Czech description
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Classification
Type
O - Miscellaneous
CEP classification
CA - Inorganic chemistry
OECD FORD branch
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Result continuities
Project
<a href="/en/project/EE2.3.20.0254" target="_blank" >EE2.3.20.0254: Research Team for Advanced Non-crystalline Materials</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2012
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů