High-Pressure Single-Crystal Neutron Scattering Study of Magnetic and Fe Vacancy Orders in （T1,Rb）：Fe4Se5 Superconductor

作     者：叶峰 鲍威 池松雪 Antonio M. dos Santos Jamie J. Molaison 方明虎 王杭栋 毛乾辉 汪晋辰 刘娟娟 盛洁明 

作者机构：Quantum Condensed Matter Division Oak Ridge National Laboratory Oak Ridge 37831 USA Department of Physics and Astronomy University of Kentucky Lexington 40506 USA Department of Physics Renmin University of China Beijing 100872 Department of Physics Zhejiang University Hangzhou 310027 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2014年第31卷第12期

页      面：111-114页

核心收录：

学科分类：080705[工学-制冷及低温工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：Supported by the National Basic Research Program of China under Grant Nos 2012CB921700  2011CBA00112  2011CBA00103 and 2012CB821404  the National Natural Science Foundation of China under Grant Nos 11034012  11190024  11374261 and 11204059  the Natural Science Foundation of Zhejiang Province under Grant No LQI2A04007  and the Scientific User Facilities Division of the Office of Basic Energy Sciences of U.S. DOE 

主　　题：NEUTRON scattering HIGH pressure (Technology) SINGLE crystals IRON compounds MAGNETIC materials VACANCIES in crystals SUPERCONDUCTORS 

摘      要：The recently discovered metal-intercalated iron selenide superconductors A2Fe4Se5 （A=K, Cs, T1- K, Rb, T1-Rb） （245） compounds, with Tc ～30K, have attracted much interest A high transition- temperature （TN ≈ 470-560K） and large magnetic moment （3.3μB/Fe） block antiferromagnetic （AFM） order exists in the superconducting samples. Mag- netic order-parameter experiences an anomaly when Tc is approached. The superconductors crystal- lize with a highly ordered √5 × √5 superstructure, in which the Fel site of the I4/m structure is only a few percents occupied and the Fe2 site is fully occupied. The non-superconducting samples at low-T also crystallize in the I4/m structure, while both Fe sites are fractionally occupied, since the numbers of the Fe vacancies in the samples and the vacant sites in the √5 × √5 pattern are mismatched. The partially ordered √5× √5 vacancy order becomes one of three competing phases for temperature below room temperature up to ～ 500K, namely, these sam- ples are phase-separated and in the miscibility gap 1lacier the n,mhi^nt condition.