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Physical mechanism of δ-δ′-ε phase stability in plutonium
Based on first-principle calculations, we have systematically explored the nature of the elastic stability and the δ-δ′-ε phase transitions in pure Pu at high temperature. It is found that, both the electron-phonon coupling and the spin fluctuation effects tend to decrease the tetragonal elastic con...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514108/ https://www.ncbi.nlm.nih.gov/pubmed/28717177 http://dx.doi.org/10.1038/s41598-017-06009-1 |
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author | Li, Chun-Mei Johansson, Börje Vitos, Levente |
author_facet | Li, Chun-Mei Johansson, Börje Vitos, Levente |
author_sort | Li, Chun-Mei |
collection | PubMed |
description | Based on first-principle calculations, we have systematically explored the nature of the elastic stability and the δ-δ′-ε phase transitions in pure Pu at high temperature. It is found that, both the electron-phonon coupling and the spin fluctuation effects tend to decrease the tetragonal elastic constant (C′) of δ-Pu, accounting for its anomalous softening at high temperature. The lattice thermal expansion together with the electron-phonon coupling can stiffen C′ of ε-Pu, promoting its mechanical stability at high temperature. The δ-ε transition is calculated to take place around 750–800 K, and is dominated by the phonon vibration. The δ′ intermediate phase is realized around 750 K mainly because of the thermal spin fluctuation. |
format | Online Article Text |
id | pubmed-5514108 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-55141082017-07-19 Physical mechanism of δ-δ′-ε phase stability in plutonium Li, Chun-Mei Johansson, Börje Vitos, Levente Sci Rep Article Based on first-principle calculations, we have systematically explored the nature of the elastic stability and the δ-δ′-ε phase transitions in pure Pu at high temperature. It is found that, both the electron-phonon coupling and the spin fluctuation effects tend to decrease the tetragonal elastic constant (C′) of δ-Pu, accounting for its anomalous softening at high temperature. The lattice thermal expansion together with the electron-phonon coupling can stiffen C′ of ε-Pu, promoting its mechanical stability at high temperature. The δ-ε transition is calculated to take place around 750–800 K, and is dominated by the phonon vibration. The δ′ intermediate phase is realized around 750 K mainly because of the thermal spin fluctuation. Nature Publishing Group UK 2017-07-17 /pmc/articles/PMC5514108/ /pubmed/28717177 http://dx.doi.org/10.1038/s41598-017-06009-1 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Li, Chun-Mei Johansson, Börje Vitos, Levente Physical mechanism of δ-δ′-ε phase stability in plutonium |
title | Physical mechanism of δ-δ′-ε phase stability in plutonium |
title_full | Physical mechanism of δ-δ′-ε phase stability in plutonium |
title_fullStr | Physical mechanism of δ-δ′-ε phase stability in plutonium |
title_full_unstemmed | Physical mechanism of δ-δ′-ε phase stability in plutonium |
title_short | Physical mechanism of δ-δ′-ε phase stability in plutonium |
title_sort | physical mechanism of δ-δ′-ε phase stability in plutonium |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514108/ https://www.ncbi.nlm.nih.gov/pubmed/28717177 http://dx.doi.org/10.1038/s41598-017-06009-1 |
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