Fabrication and characterization of SmO_(0.7)F_(0.2)FeAs bulk with a transition temperature of 56.5 K  

作　　者：LIU Zhiyong MA Lin ZHAO Junjing YAN Binjie SUO Hongli 

机构地区：[1]College of Materials Science and Engineering, Beijing University of Technology, Beijing 100022, China [2]Department of Physics, University oflUinois at Chicago, Chicago, IL 60607, America [3]Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, America

出　　处：《Rare Metals》2011年第5期496-500,共5页稀有金属（英文版）

基　　金：supported by the National Basic Research Program of China (No. 2006CB601005);the National High Technology Research and Development Program of China (No. 2009AA032401);the National Natural Science Foundation of China (Nos. 50771003 and 50802004);the Beijing Municipal Natural Science Foundation (No. 2092006);the Program for New Century Excellent Talents in University of Ministry of Education of China (No. 39009001201002)

摘　　要：The superconductivity of iron-based superconductor SmO 0.7 F 0.2 FeAs was investigated. The SmO 0.7 F 0.2 FeAs sample was prepared by the two-step solid-state reaction method. The onset resistivity transition temperature is as high as 56.5 K. X-ray diffraction （XRD） results show that the lattice parameters a and c are 0.39261 and 0.84751 nm, respectively. Furthermore, the global J c was more than 2.3 × 10 5 A/cm 2 at T = 10 K and H = 9 T, which was calculated by the formula of J c = 20ΔM/[a（1-a/（3b））]. The upper critical fields, H c2 ≈ 256 T （T = 0 K）, was determined according to the Werthamer-Helfand-Hohenberg formula, indicating that the SmO 0.7 F 0.2 FeAs was a superconductor with a very promising application.The superconductivity of iron-based superconductor SmO 0.7 F 0.2 FeAs was investigated. The SmO 0.7 F 0.2 FeAs sample was prepared by the two-step solid-state reaction method. The onset resistivity transition temperature is as high as 56.5 K. X-ray diffraction （XRD） results show that the lattice parameters a and c are 0.39261 and 0.84751 nm, respectively. Furthermore, the global J c was more than 2.3 × 10 5 A/cm 2 at T = 10 K and H = 9 T, which was calculated by the formula of J c = 20ΔM/[a（1-a/（3b））]. The upper critical fields, H c2 ≈ 256 T （T = 0 K）, was determined according to the Werthamer-Helfand-Hohenberg formula, indicating that the SmO 0.7 F 0.2 FeAs was a superconductor with a very promising application.

关 键 词：iron-based superconductor SUPERCONDUCTIVITY solid-state reaction transition temperature 

分 类 号：O484.1[理学—固体物理] TP391.72[理学—物理]