title: Development of very high Jc in Ba(Fe1-xCox)2As2 thin films grown on CaF2.
abstract: Ba(Fe(1-x)Co(x))(2)As(2) is the most tunable of the Fe-based superconductors (FBS) in terms of acceptance of high densities of self-assembled and artificially introduced pinning centres which are effective in significantly increasing the critical current density, J(c). Moreover, FBS are very sensitive to strain, which induces an important enhancement in critical temperature, T(c), of the material. In this paper we demonstrate that strain induced by the substrate can further improve J(c) of both single and multilayer films by more than that expected simply due to the increase in T(c). The multilayer deposition of Ba(Fe(1-x)Co(x))(2)As(2) on CaF2 increases the pinning force density (F(p) = J(c) × µ0H) by more than 60% compared to a single layer film, reaching a maximum of 84 GN/m(3) at 22.5 T and 4.2 K, the highest value ever reported in any 122 phase.
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: C
authors.initials: C
authors.lastname: Tarantini
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: F
authors.initials: F
authors.lastname: Kametani
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: J
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Weiss
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: J
authors.initials: J
authors.lastname: Jaroszynski
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: E E
authors.initials: EE
authors.lastname: Hellstrom
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Eom
authors.affiliation: Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University, Tallahassee FL 32310, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Larbalestier