Superconductivity Tuned by the Iron Vacancy Order in KxFe2?ySe2
BAO Wei1**, LI Guan-Nan2,3, HUANG Qing-Zhen2, CHEN Gen-Fu1, HE Jun-Bao1, WANG Du-Ming1, M. A. Green2,4, QIU Yi-Ming2,4, LUO Jian-Lin3, WU Mei-Mei5
1Department of Physics, Renmin University of China, Beijing 100872 2NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA 3Institute of Physics, Chinese Academy of Sciences, Beijing 100190 4Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA 5Neutron Scattering Laboratory, China Institute of Atomic Energy, Beijing 102413
Abstract：Combining in-depth neutron diffraction and systematic bulk studies, we discover that the √5×√5 Fe vacancy order, with its associated block antiferromagnetic order, is the ground state with varying occupancy ratios of the iron 16#em/em# and vacancy 4d sites across the phase-diagram of KxFe2?ySe2. The orthorhombic order, with one of the four Fe sites vacant, appears only at intermediate temperatures as a competing phase. The material experiences an insulator to metal crossover when the √5×√5 order is highly developed. Superconductivity occurs in such a metallic phase.
(Intrinsic properties of magnetically ordered materials)
引用本文:
. [J]. 中国物理快报, 2013, 30(2): 27402-027402.
BAO Wei, LI Guan-Nan, HUANG Qing-Zhen, CHEN Gen-Fu, HE Jun-Bao, WANG Du-Ming, M. A. Green, QIU Yi-Ming, LUO Jian-Lin, WU Mei-Mei. Superconductivity Tuned by the Iron Vacancy Order in KxFe2?ySe2. Chin. Phys. Lett., 2013, 30(2): 27402-027402.
2013, Vol. 30 
