Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure
A systematic study of the crystal structure of a layered iron oxypnictide LaFeAsO1−xHx as a function of pressure was performed using synchrotron X-ray diffraction. This compound exhibits a unique phase diagram of two superconducting phases and two parent phases. We established that the As–Fe–As angl...
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| Format: | Online |
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Nature Publishing Group
2016
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5177881/ |
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pubmed-51778812016-12-29 Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure Kobayashi, Kensuke Yamaura, Jun-ichi Iimura, Soshi Maki, Sachiko Sagayama, Hajime Kumai, Reiji Murakami, Youichi Takahashi, Hiroki Matsuishi, Satoru Hosono, Hideo Article A systematic study of the crystal structure of a layered iron oxypnictide LaFeAsO1−xHx as a function of pressure was performed using synchrotron X-ray diffraction. This compound exhibits a unique phase diagram of two superconducting phases and two parent phases. We established that the As–Fe–As angle of the FeAs4 tetrahedron widens on the application of pressure due to the interspace between the layers being nearly infilled by the large La and As atoms. Such rarely observed behaviour in iron pnictides implies that the FeAs4 coordination deviates from the regular tetrahedron in the present systems. This breaks a widely accepted structural guide that the superconductivity favours the regular tetrahedron, albeit the superconducting transition temperature (Tc) increases from 18 K at ambient pressure to 52 K at 6 GPa for x = 0.2. In the phase diagram, the second parent phase at x ~ 0.5 is suppressed by pressure as low as ~1.5 GPa in contrast to the first parent phase at x ~ 0, which is robust against pressure. We suggest that certain spin-fluctuation from the second parent phase is strongly related to high-Tc under pressure. Nature Publishing Group 2016-12-22 /pmc/articles/PMC5177881/ /pubmed/28004768 http://dx.doi.org/10.1038/srep39646 Text en Copyright © 2016, The Author(s) 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/ |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Kobayashi, Kensuke Yamaura, Jun-ichi Iimura, Soshi Maki, Sachiko Sagayama, Hajime Kumai, Reiji Murakami, Youichi Takahashi, Hiroki Matsuishi, Satoru Hosono, Hideo |
| spellingShingle |
Kobayashi, Kensuke Yamaura, Jun-ichi Iimura, Soshi Maki, Sachiko Sagayama, Hajime Kumai, Reiji Murakami, Youichi Takahashi, Hiroki Matsuishi, Satoru Hosono, Hideo Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure |
| author_facet |
Kobayashi, Kensuke Yamaura, Jun-ichi Iimura, Soshi Maki, Sachiko Sagayama, Hajime Kumai, Reiji Murakami, Youichi Takahashi, Hiroki Matsuishi, Satoru Hosono, Hideo |
| author_sort |
Kobayashi, Kensuke |
| title |
Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure |
| title_short |
Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure |
| title_full |
Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure |
| title_fullStr |
Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure |
| title_full_unstemmed |
Pressure effect on iron-based superconductor LaFeAsO1−xHx: Peculiar response of 1111-type structure |
| title_sort |
pressure effect on iron-based superconductor lafeaso1−xhx: peculiar response of 1111-type structure |
| description |
A systematic study of the crystal structure of a layered iron oxypnictide LaFeAsO1−xHx as a function of pressure was performed using synchrotron X-ray diffraction. This compound exhibits a unique phase diagram of two superconducting phases and two parent phases. We established that the As–Fe–As angle of the FeAs4 tetrahedron widens on the application of pressure due to the interspace between the layers being nearly infilled by the large La and As atoms. Such rarely observed behaviour in iron pnictides implies that the FeAs4 coordination deviates from the regular tetrahedron in the present systems. This breaks a widely accepted structural guide that the superconductivity favours the regular tetrahedron, albeit the superconducting transition temperature (Tc) increases from 18 K at ambient pressure to 52 K at 6 GPa for x = 0.2. In the phase diagram, the second parent phase at x ~ 0.5 is suppressed by pressure as low as ~1.5 GPa in contrast to the first parent phase at x ~ 0, which is robust against pressure. We suggest that certain spin-fluctuation from the second parent phase is strongly related to high-Tc under pressure. |
| publisher |
Nature Publishing Group |
| publishDate |
2016 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5177881/ |
| _version_ |
1613811096585502720 |