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Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures
Magnetite exhibits unique electronic, magnetic, and structural properties in extreme conditions that are of great research interest. Previous studies have suggested a number of transitional models, although the nature of magnetite at high pressure remains elusive. We have studied a highly stoichiome...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153994/ https://www.ncbi.nlm.nih.gov/pubmed/25186916 http://dx.doi.org/10.1038/srep06282 |
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author | Lin, Jung-Fu Wu, Junjie Zhu, Jie Mao, Zhu Said, Ayman H. Leu, Bogdan M. Cheng, Jinguang Uwatoko, Yoshiya Jin, Changqing Zhou, Jianshi |
author_facet | Lin, Jung-Fu Wu, Junjie Zhu, Jie Mao, Zhu Said, Ayman H. Leu, Bogdan M. Cheng, Jinguang Uwatoko, Yoshiya Jin, Changqing Zhou, Jianshi |
author_sort | Lin, Jung-Fu |
collection | PubMed |
description | Magnetite exhibits unique electronic, magnetic, and structural properties in extreme conditions that are of great research interest. Previous studies have suggested a number of transitional models, although the nature of magnetite at high pressure remains elusive. We have studied a highly stoichiometric magnetite using inelastic X-ray scattering, X-ray diffraction and emission, and Raman spectroscopies in diamond anvil cells up to ~20 GPa, while complementary electrical conductivity measurements were conducted in a cubic anvil cell up to 8.5 GPa. We have observed an elastic softening in the diagonal elastic constants (C(11) and C(44)) and a hardening in the off-diagonal constant (C(12)) at ~8 GPa where significant elastic anisotropies in longitudinal and transverse acoustic waves occur, especially along the [110] direction. An additional vibrational Raman band between the A(1g) and T(2g) modes was also detected at the transition pressure. These abnormal elastic and vibrational behaviors of magnetite are attributed to the occurrence of the octahedrally-coordinated Fe(2+)-Fe(3+)-Fe(2+) ions charge-ordering along the [110] direction in the inverse spinel structure. We propose a new phase diagram of magnetite in which the temperature for the metal-insulator and distorted structural transitions decreases with increasing pressure while the charge-ordering transition occurs at ~8 GPa and room temperature. |
format | Online Article Text |
id | pubmed-4153994 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-41539942014-09-10 Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures Lin, Jung-Fu Wu, Junjie Zhu, Jie Mao, Zhu Said, Ayman H. Leu, Bogdan M. Cheng, Jinguang Uwatoko, Yoshiya Jin, Changqing Zhou, Jianshi Sci Rep Article Magnetite exhibits unique electronic, magnetic, and structural properties in extreme conditions that are of great research interest. Previous studies have suggested a number of transitional models, although the nature of magnetite at high pressure remains elusive. We have studied a highly stoichiometric magnetite using inelastic X-ray scattering, X-ray diffraction and emission, and Raman spectroscopies in diamond anvil cells up to ~20 GPa, while complementary electrical conductivity measurements were conducted in a cubic anvil cell up to 8.5 GPa. We have observed an elastic softening in the diagonal elastic constants (C(11) and C(44)) and a hardening in the off-diagonal constant (C(12)) at ~8 GPa where significant elastic anisotropies in longitudinal and transverse acoustic waves occur, especially along the [110] direction. An additional vibrational Raman band between the A(1g) and T(2g) modes was also detected at the transition pressure. These abnormal elastic and vibrational behaviors of magnetite are attributed to the occurrence of the octahedrally-coordinated Fe(2+)-Fe(3+)-Fe(2+) ions charge-ordering along the [110] direction in the inverse spinel structure. We propose a new phase diagram of magnetite in which the temperature for the metal-insulator and distorted structural transitions decreases with increasing pressure while the charge-ordering transition occurs at ~8 GPa and room temperature. Nature Publishing Group 2014-09-04 /pmc/articles/PMC4153994/ /pubmed/25186916 http://dx.doi.org/10.1038/srep06282 Text en Copyright © 2014, Macmillan Publishers Limited. All rights reserved 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 in order to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article Lin, Jung-Fu Wu, Junjie Zhu, Jie Mao, Zhu Said, Ayman H. Leu, Bogdan M. Cheng, Jinguang Uwatoko, Yoshiya Jin, Changqing Zhou, Jianshi Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures |
title | Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures |
title_full | Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures |
title_fullStr | Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures |
title_full_unstemmed | Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures |
title_short | Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures |
title_sort | abnormal elastic and vibrational behaviors of magnetite at high pressures |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153994/ https://www.ncbi.nlm.nih.gov/pubmed/25186916 http://dx.doi.org/10.1038/srep06282 |
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