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Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films
The underlying mechanism driving the structural amorphous-to-crystalline transition in Group VI chalcogenides is still a matter of debate even in the simplest GeTe system. We exploit the extreme sensitivity of 57Fe emission Mössbauer spectroscopy, following dilute implantation of 57Mn (T½ = 1.5 m...
Autores principales: | , , , , , , , , , , , , , , , , |
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Publicado: |
2017
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Acceso en línea: | https://dx.doi.org/10.1038/s41598-017-08275-5 http://cds.cern.ch/record/2280772 |
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author | Mantovan, R. Fallica, R. Mokhles Gerami, A. Mølholt, T. E. Wiemer, C. Longo, M. Gunnlaugsson, H. P. Johnston, K. Masenda, H. Naidoo, D. Ncube, M. Bharuth-Ram, K. Fanciulli, M. Gislason, H. P. Langouche, G. Ólafsson, S. Weyer, G. |
author_facet | Mantovan, R. Fallica, R. Mokhles Gerami, A. Mølholt, T. E. Wiemer, C. Longo, M. Gunnlaugsson, H. P. Johnston, K. Masenda, H. Naidoo, D. Ncube, M. Bharuth-Ram, K. Fanciulli, M. Gislason, H. P. Langouche, G. Ólafsson, S. Weyer, G. |
author_sort | Mantovan, R. |
collection | CERN |
description | The underlying mechanism driving the structural amorphous-to-crystalline transition in Group VI chalcogenides is still a matter of debate even in the simplest GeTe system. We exploit the extreme sensitivity of 57Fe emission Mössbauer spectroscopy, following dilute implantation of 57Mn (T½ = 1.5 min) at ISOLDE/CERN, to study the electronic charge distribution in the immediate vicinity of the 57Fe probe substituting Ge (FeGe), and to interrogate the local environment of FeGe over the amorphous-crystalline phase transition in GeTe thin films. Our results show that the local structure of as-sputtered amorphous GeTe is a combination of tetrahedral and defect-octahedral sites. The main effect of the crystallization is the conversion from tetrahedral to defect-free octahedral sites. We discover that only the tetrahedral fraction in amorphous GeTe participates to the change of the FeGe-Te chemical bonds, with a net electronic charge density transfer of ~ 1.6 e/a0 between FeGe and neighboring Te atoms. This charge transfer accounts for a lowering of the covalent character during crystallization. The results are corroborated by theoretical calculations within the framework of density functional theory. The observed atomic-scale chemical-structural changes are directly connected to the macroscopic phase transition and resistivity switch of GeTe thin films. |
id | cern-2280772 |
institution | Organización Europea para la Investigación Nuclear |
publishDate | 2017 |
record_format | invenio |
spelling | cern-22807722022-07-08T07:11:39Zdoi:10.1038/s41598-017-08275-5http://cds.cern.ch/record/2280772Mantovan, R.Fallica, R.Mokhles Gerami, A.Mølholt, T. E.Wiemer, C.Longo, M.Gunnlaugsson, H. P.Johnston, K.Masenda, H.Naidoo, D.Ncube, M.Bharuth-Ram, K.Fanciulli, M.Gislason, H. P.Langouche, G.Ólafsson, S.Weyer, G.Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin filmsThe underlying mechanism driving the structural amorphous-to-crystalline transition in Group VI chalcogenides is still a matter of debate even in the simplest GeTe system. We exploit the extreme sensitivity of 57Fe emission Mössbauer spectroscopy, following dilute implantation of 57Mn (T½ = 1.5 min) at ISOLDE/CERN, to study the electronic charge distribution in the immediate vicinity of the 57Fe probe substituting Ge (FeGe), and to interrogate the local environment of FeGe over the amorphous-crystalline phase transition in GeTe thin films. Our results show that the local structure of as-sputtered amorphous GeTe is a combination of tetrahedral and defect-octahedral sites. The main effect of the crystallization is the conversion from tetrahedral to defect-free octahedral sites. We discover that only the tetrahedral fraction in amorphous GeTe participates to the change of the FeGe-Te chemical bonds, with a net electronic charge density transfer of ~ 1.6 e/a0 between FeGe and neighboring Te atoms. This charge transfer accounts for a lowering of the covalent character during crystallization. The results are corroborated by theoretical calculations within the framework of density functional theory. The observed atomic-scale chemical-structural changes are directly connected to the macroscopic phase transition and resistivity switch of GeTe thin films.oai:cds.cern.ch:22807722017 |
spellingShingle | Mantovan, R. Fallica, R. Mokhles Gerami, A. Mølholt, T. E. Wiemer, C. Longo, M. Gunnlaugsson, H. P. Johnston, K. Masenda, H. Naidoo, D. Ncube, M. Bharuth-Ram, K. Fanciulli, M. Gislason, H. P. Langouche, G. Ólafsson, S. Weyer, G. Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films |
title | Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films |
title_full | Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films |
title_fullStr | Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films |
title_full_unstemmed | Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films |
title_short | Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films |
title_sort | atomic-scale study of the amorphous-to-crystalline phase transition mechanism in gete thin films |
url | https://dx.doi.org/10.1038/s41598-017-08275-5 http://cds.cern.ch/record/2280772 |
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