title: Low-temperature rapid synthesis and superconductivity of Fe-based oxypnictide superconductors.
abstract: Fe-based oxypnictide superconductors were successfully synthesized at lower reaction temperatures and with shorter reaction times made possible by starting with less stable compounds, which provide a larger driving force for reactions. Using ball-milled powders of intermediate compounds, phase-pure superconductors with T(c) above 50 K were synthesized at 1173 K in 20 min. This method is particularly advantageous for retaining F, a volatile dopant that enhances superconductivity. Bulk superconductivity and high upper critical fields up to 392 T in Sm(0.85)Nd(0.15)FeAsO(0.85)F(0.15) were demonstrated.
authors.affiliation: CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Fang
authors.forename: Fu-Qiang
authors.initials: FQ
authors.lastname: Huang
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Xie
authors.forename: Mian-Heng
authors.initials: MH
authors.lastname: Jiang