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Title: Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe 2 As 2 Superconductors

Abstract

Combined scanning tunneling microscopy, spectroscopy, and local barrier height (LBH) studies show that low-temperature-cleaved optimally doped Ba(Fe 1–xCo x) 2As 2 crystals with x = 0.06, with T c = 22 K, have complicated morphologies. Although the cleavage surface and hence the morphologies are variable, the superconducting gap maps show the same gap widths and nanometer size inhomogeneities irrelevant to the morphology. Based on the spectroscopy and LBH maps, the bright patches and dark stripes in the morphologies are identified as Ba- and As-dominated surface terminations, respectively. Magnetic impurities, possibly due to Co or Fe atoms, are believed to create local in-gap state and, in addition, suppress the superconducting coherence peaks. Lastly, this study will clarify the confusion on the cleavage surface terminations of the Fe-based superconductors and its relation with the electronic structures.

Authors:
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Publication Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1342685
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 17; Journal Issue: 3; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Zou, Qiang, Wu, Zhiming, Fu, Mingming, Zhang, Chunmiao, Rajput, S., Wu, Yaping, Li, Li, Parker, D. S., Kang, Junyong, Sefat, A. S., and Gai, Zheng. Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe 2 As 2 Superconductors. United States: N. p., 2017. Web. doi:10.1021/acs.nanolett.6b04825.
Zou, Qiang, Wu, Zhiming, Fu, Mingming, Zhang, Chunmiao, Rajput, S., Wu, Yaping, Li, Li, Parker, D. S., Kang, Junyong, Sefat, A. S., & Gai, Zheng. Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe 2 As 2 Superconductors. United States. doi:10.1021/acs.nanolett.6b04825.
Zou, Qiang, Wu, Zhiming, Fu, Mingming, Zhang, Chunmiao, Rajput, S., Wu, Yaping, Li, Li, Parker, D. S., Kang, Junyong, Sefat, A. S., and Gai, Zheng. Fri . "Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe 2 As 2 Superconductors". United States. doi:10.1021/acs.nanolett.6b04825. https://www.osti.gov/servlets/purl/1342685.
@article{osti_1342685,
title = {Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe 2 As 2 Superconductors},
author = {Zou, Qiang and Wu, Zhiming and Fu, Mingming and Zhang, Chunmiao and Rajput, S. and Wu, Yaping and Li, Li and Parker, D. S. and Kang, Junyong and Sefat, A. S. and Gai, Zheng},
abstractNote = {Combined scanning tunneling microscopy, spectroscopy, and local barrier height (LBH) studies show that low-temperature-cleaved optimally doped Ba(Fe1–xCox)2As2 crystals with x = 0.06, with Tc = 22 K, have complicated morphologies. Although the cleavage surface and hence the morphologies are variable, the superconducting gap maps show the same gap widths and nanometer size inhomogeneities irrelevant to the morphology. Based on the spectroscopy and LBH maps, the bright patches and dark stripes in the morphologies are identified as Ba- and As-dominated surface terminations, respectively. Magnetic impurities, possibly due to Co or Fe atoms, are believed to create local in-gap state and, in addition, suppress the superconducting coherence peaks. Lastly, this study will clarify the confusion on the cleavage surface terminations of the Fe-based superconductors and its relation with the electronic structures.},
doi = {10.1021/acs.nanolett.6b04825},
journal = {Nano Letters},
number = 3,
volume = 17,
place = {United States},
year = {Fri Feb 03 00:00:00 EST 2017},
month = {Fri Feb 03 00:00:00 EST 2017}
}

Journal Article:
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