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ID 55642
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Zheng, Lu Research Laboratory for Surface Science, Okayama University
Miao, Xiao Research Laboratory for Surface Science, Okayama University
Sakai, Yusuke Research Laboratory for Surface Science, Okayama University
Goto, Hidenori Research Laboratory for Surface Science, Okayama University
Uesugi, Eri Research Laboratory for Surface Science, Okayama University
Eguchi, Ritsuko Research Laboratory for Surface Science, Okayama University
Nishiyama, Saki Research Laboratory for Surface Science, Okayama University
Sugimoto, Kunihisa Japan Synchrotron Radiation Research Institute, SPring-8
Fujiwara, Akihiko Department of Nanotechnology for Sustainable Energy, Kwansei Gakuin University
Kubozono, Yoshihiro Research Centre of New Functional Materials for Energy Production, Storage and Transport, Okayama University
Abstract
The superconducting transition temperature T-c of ammoniated metal-doped FeSe (NH3)(y)MxFeSe (M: metal atom) has been scaled with the FeSe plane spacing, and it has been suggested that the FeSe plane spacing depends on the location of metal atoms in (NH3)(y)MxFeSe crystals. Although the crystal structure of (NH3)(y)LixFeSe exhibiting a high T-c (similar to 44 K) was determined from neutron diffraction, the structure of (NH3)(y)MxFeSe exhibiting a low T-c (similar to 32 K) has not been determined thus far. Here, we determined the crystal structure of (NH3)(y)Cs0.4FeSe (T-c = 33 K) through the Rietveld refinement of the x-ray diffraction (XRD) pattern measured with synchrotron radiation at 30 K. The XRD pattern was analyzed based on two different models, on-center and off-center, under a space group of 14/mmm. In the on-center structure, the Cs occupies the 2a site and the N of NH3 may occupy either the 4c or 2b site, or both. In the off-center structure, the Cs may occupy either the 4c or 2b site, or both, while the N occupies the 2a site. Only an on-center structure model in which the Cs occupies the 2a and the N of NH3 occupies the 4c site provided reasonable results in the Rietveld analysis. Consequently, we concluded that (NH3)(y)Cs0.4FeSe can be assigned to the on-center structure, which produces a smaller FeSe plane spacing leading to the lower T-c.
Note
This is an article published by American Physical Society
Published Date
2016-03
Publication Title
Physical Review B
Volume
volume93
Issue
issue10
Publisher
American Physical Society
Start Page
104508
ISSN
2469-9950
NCID
AA11187113
Content Type
Journal Article
language
英語
OAI-PMH Set
岡山大学
Copyright Holders
American Physical Society
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DOI
Web of Sience KeyUT
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isVersionOf https://doi.org/10.1103/PhysRevB.93.104508