文章基本信息

标题：Large-moment antiferromagnetic order in overdoped high-Tc superconductor 154SmFeAsO1−xDx
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作者：Soshi Iimura ; Hiroshi Okanishi ; Satoru Matsuishi 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2017
卷号：114
期号：22
页码：E4354-E4359
DOI：10.1073/pnas.1703295114
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In iron-based superconductors, high critical temperature ( T _c) superconductivity over 50 K has only been accomplished in electron-doped hRE FeAsO ( hRE is heavy rare earth ( RE ) element). Although hRE FeAsO has the highest bulk T _c (58 K), progress in understanding its physical properties has been relatively slow due to difficulties in achieving high-concentration electron doping and carrying out neutron experiments. Here, we present a systematic neutron powder diffraction study of ¹⁵⁴SmFeAsO_{1− x}D_x, and the discovery of a long-range antiferromagnetic ordering with x ≥ 0.56 (AFM2) accompanying a structural transition from tetragonal to orthorhombic. Surprisingly, the Fe magnetic moment in AFM2 reaches a magnitude of 2.73 μ_B/Fe, which is the largest in all nondoped iron pnictides and chalcogenides. Theoretical calculations suggest that the AFM2 phase originates in kinetic frustration of the Fe-3 d _xy orbital, in which the nearest-neighbor hopping parameter becomes zero. The unique phase diagram, i.e., highest- T _c superconducting phase adjacent to the strongly correlated phase in electron-overdoped regime, yields important clues to the unconventional origins of superconductivity.
关键词：high- T _c superconductivity ; neutron scattering ; oxyhydrides ; iron-based superconductors ; antiferromagnetism