Cargando…

Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)

Because of their robust switching capability, chalcogenide glass materials have been used for a wide range of applications, including optical storages devices. These phase transitions are achieved by laser irradiation via thermal processes. Recent studies have suggested the potential of nonthermal p...

Descripción completa

Detalles Bibliográficos
Autores principales: Hada, Masaki, Oba, Wataru, Kuwahara, Masashi, Katayama, Ikufumi, Saiki, Toshiharu, Takeda, Jun, Nakamura, Kazutaka G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4551965/
https://www.ncbi.nlm.nih.gov/pubmed/26314613
http://dx.doi.org/10.1038/srep13530
_version_ 1782387657065627648
author Hada, Masaki
Oba, Wataru
Kuwahara, Masashi
Katayama, Ikufumi
Saiki, Toshiharu
Takeda, Jun
Nakamura, Kazutaka G.
author_facet Hada, Masaki
Oba, Wataru
Kuwahara, Masashi
Katayama, Ikufumi
Saiki, Toshiharu
Takeda, Jun
Nakamura, Kazutaka G.
author_sort Hada, Masaki
collection PubMed
description Because of their robust switching capability, chalcogenide glass materials have been used for a wide range of applications, including optical storages devices. These phase transitions are achieved by laser irradiation via thermal processes. Recent studies have suggested the potential of nonthermal phase transitions in the chalcogenide glass material Ge(2)Sb(2)Te(5) triggered by ultrashort optical pulses; however, a detailed understanding of the amorphization and damage mechanisms governed by nonthermal processes is still lacking. Here we performed ultrafast time-resolved electron diffraction and single-shot optical pump-probe measurements followed by femtosecond near-ultraviolet pulse irradiation to study the structural dynamics of polycrystalline Ge(2)Sb(2)Te(5). The experimental results present a nonthermal crystal-to-amorphous phase transition of Ge(2)Sb(2)Te(5) initiated by the displacements of Ge atoms. Above the fluence threshold, we found that the permanent amorphization caused by multi-displacement effects is accompanied by a partial hexagonal crystallization.
format Online
Article
Text
id pubmed-4551965
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Nature Publishing Group
record_format MEDLINE/PubMed
spelling pubmed-45519652015-09-04 Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5) Hada, Masaki Oba, Wataru Kuwahara, Masashi Katayama, Ikufumi Saiki, Toshiharu Takeda, Jun Nakamura, Kazutaka G. Sci Rep Article Because of their robust switching capability, chalcogenide glass materials have been used for a wide range of applications, including optical storages devices. These phase transitions are achieved by laser irradiation via thermal processes. Recent studies have suggested the potential of nonthermal phase transitions in the chalcogenide glass material Ge(2)Sb(2)Te(5) triggered by ultrashort optical pulses; however, a detailed understanding of the amorphization and damage mechanisms governed by nonthermal processes is still lacking. Here we performed ultrafast time-resolved electron diffraction and single-shot optical pump-probe measurements followed by femtosecond near-ultraviolet pulse irradiation to study the structural dynamics of polycrystalline Ge(2)Sb(2)Te(5). The experimental results present a nonthermal crystal-to-amorphous phase transition of Ge(2)Sb(2)Te(5) initiated by the displacements of Ge atoms. Above the fluence threshold, we found that the permanent amorphization caused by multi-displacement effects is accompanied by a partial hexagonal crystallization. Nature Publishing Group 2015-08-28 /pmc/articles/PMC4551965/ /pubmed/26314613 http://dx.doi.org/10.1038/srep13530 Text en Copyright © 2015, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Hada, Masaki
Oba, Wataru
Kuwahara, Masashi
Katayama, Ikufumi
Saiki, Toshiharu
Takeda, Jun
Nakamura, Kazutaka G.
Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)
title Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)
title_full Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)
title_fullStr Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)
title_full_unstemmed Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)
title_short Ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-UV photoexcitation-induced amorphization in Ge(2)Sb(2)Te(5)
title_sort ultrafast time-resolved electron diffraction revealing the nonthermal dynamics of near-uv photoexcitation-induced amorphization in ge(2)sb(2)te(5)
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4551965/
https://www.ncbi.nlm.nih.gov/pubmed/26314613
http://dx.doi.org/10.1038/srep13530
work_keys_str_mv AT hadamasaki ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5
AT obawataru ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5
AT kuwaharamasashi ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5
AT katayamaikufumi ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5
AT saikitoshiharu ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5
AT takedajun ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5
AT nakamurakazutakag ultrafasttimeresolvedelectrondiffractionrevealingthenonthermaldynamicsofnearuvphotoexcitationinducedamorphizationinge2sb2te5