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Title: Enhanced superconductivity of SmFeAsO co-doped by Scandium and Fluorine to increase chemical inner pressure

Journal Article · · Journal of Solid State Chemistry
; ; ;  [1];  [1]; ;  [2]
  1. CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)
  2. State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

Sm{sub 1-x/3}Sc{sub x/3}FeAsO{sub 1-x}F{sub x} (x=0.09-0.27) were synthesized by the mechanical alloying and subsequent low temperature rapid sintering (2 h at 950 Degree-Sign C). The superconducting transition temperature (T{sub c}) increased with the doping level of x. The optimal doping achieved a T{sub c} up to 53.5 K in Sm{sub 0.93}Sc{sub 0.07}FeAsO{sub 0.79}F{sub 0.21}. The higher T{sub c} value was attributed to the increased chemical inner pressure from local lattice distortion induced by smaller-size dopants, which was further confirmed by Sm{sub 1-x}Sc{sub x}FeAsO{sub 0.88}F{sub 0.12} (x=0.04, 0.08, 0.12). Accordingly, larger lattice distortion can enhance the superconductivity below the doping limit. Similar phenomenon was also observed in the La{sub 1-x}Y{sub x}FeAsO{sub 0.8}F{sub 0.2} (x=0.4, 0.5, 0.6). - Graphical abstract: The introduction of Sc{sup 3+} and F{sup -} in SmFeAsO leads to higher chemical inner pressure generated by larger lattice distortion, which is the reason of the improved T{sub c}. Highlights: Black-Right-Pointing-Pointer The superconducting properties of Sm{sub 1-x/3}Sc{sub x/3}FeAsO{sub 1-x}F{sub x} are investigated. Black-Right-Pointing-Pointer The co-doping of Sc{sup 3+} and F{sup -} in SmFeAsO leads to higher chemical inner pressure. Black-Right-Pointing-Pointer Higher chemical inner pressure is beneficial to the superconductivity. Black-Right-Pointing-Pointer The co-doped samples of La{sub 1-x}Y{sub x}FeAsO{sub 0.8}F{sub 0.2} further demonstrate the assumption.

OSTI ID:
22149828
Journal Information:
Journal of Solid State Chemistry, Vol. 194; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
Country of Publication:
United States
Language:
English