Fevacancy ordering in superconducting K _{1–x}Fe _{2–y}Se _{2}: Firstprinciples calculations and Monte Carlo simulations
Fe vacancies in the 33 K superconductor K _{1–x}Fe _{2–y}Se _{2} show ordering schemes that may be correlated with its superconducting properties. Firstprinciples calculations and kinetic Monte Carlo simulations lead to a very simple model for vacancy ordering. Repulsive dipolar interactions between Fe vacancies show three ground states: a $$\sqrt{8}\times \sqrt{10}$$ rhombusordered structure for 12.5% vacancies, a $$\sqrt{5}\times \sqrt{5}$$ squared lattice for 20% vacancies, and a $$\sqrt{5}\times \sqrt{5}$$ rhombusordered structure for 25% vacancies. Other structural states are derived from these three ground states and may contain additional disordered spatial regions. As a result, the repulsive interaction between Fe vacancies arises from enhanced Fe–Se covalent bonds, which differs from the wellknown attractive interaction of Fe vacancies in bodycentered cubic Fe.
 Authors:

^{[1]};
^{[2]};
^{[1]};
^{[1]};
^{[1]};
^{[1]};
^{[3]}
 Xi'an Jiaotong Univ., Xi'an (China)
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Xi'an Jiaotong Univ., Xi'an (China); Univ. of Cambridge, Cambridge (United Kingdom)
 Publication Date:
 Report Number(s):
 LAUR1523116
Journal ID: ISSN 09532048
 Grant/Contract Number:
 AC5206NA25396
 Type:
 Accepted Manuscript
 Journal Name:
 Superconductor Science and Technology
 Additional Journal Information:
 Journal Volume: 28; Journal Issue: 9; Journal ID: ISSN 09532048
 Publisher:
 IOP Publishing
 Research Org:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org:
 USDOE Laboratory Directed Research and Development (LDRD) Program
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; material science
 OSTI Identifier:
 1329680
Fang, Yong, Tai, Yuan Yen, Deng, Junkai, Wu, Chao, Ding, Xiangdong, Sun, Jun, and Salje, Ekhard K. H.. Fevacancy ordering in superconducting K1–xFe2–ySe2: Firstprinciples calculations and Monte Carlo simulations. United States: N. p.,
Web. doi:10.1088/09532048/28/9/095004.
Fang, Yong, Tai, Yuan Yen, Deng, Junkai, Wu, Chao, Ding, Xiangdong, Sun, Jun, & Salje, Ekhard K. H.. Fevacancy ordering in superconducting K1–xFe2–ySe2: Firstprinciples calculations and Monte Carlo simulations. United States. doi:10.1088/09532048/28/9/095004.
Fang, Yong, Tai, Yuan Yen, Deng, Junkai, Wu, Chao, Ding, Xiangdong, Sun, Jun, and Salje, Ekhard K. H.. 2015.
"Fevacancy ordering in superconducting K1–xFe2–ySe2: Firstprinciples calculations and Monte Carlo simulations". United States.
doi:10.1088/09532048/28/9/095004. https://www.osti.gov/servlets/purl/1329680.
@article{osti_1329680,
title = {Fevacancy ordering in superconducting K1–xFe2–ySe2: Firstprinciples calculations and Monte Carlo simulations},
author = {Fang, Yong and Tai, Yuan Yen and Deng, Junkai and Wu, Chao and Ding, Xiangdong and Sun, Jun and Salje, Ekhard K. H.},
abstractNote = {Fe vacancies in the 33 K superconductor K1–xFe2–ySe2 show ordering schemes that may be correlated with its superconducting properties. Firstprinciples calculations and kinetic Monte Carlo simulations lead to a very simple model for vacancy ordering. Repulsive dipolar interactions between Fe vacancies show three ground states: a $\sqrt{8}\times \sqrt{10}$ rhombusordered structure for 12.5% vacancies, a $\sqrt{5}\times \sqrt{5}$ squared lattice for 20% vacancies, and a $\sqrt{5}\times \sqrt{5}$ rhombusordered structure for 25% vacancies. Other structural states are derived from these three ground states and may contain additional disordered spatial regions. As a result, the repulsive interaction between Fe vacancies arises from enhanced Fe–Se covalent bonds, which differs from the wellknown attractive interaction of Fe vacancies in bodycentered cubic Fe.},
doi = {10.1088/09532048/28/9/095004},
journal = {Superconductor Science and Technology},
number = 9,
volume = 28,
place = {United States},
year = {2015},
month = {7}
}