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Title: Development of very high J c in Ba(Fe 1-xCo x) 2As 2 thin films grown on CaF 2

Ba(Fe 1-xCo x) 2As 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 study 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-xCo x) 2As 2 on CaF 2 increases the pinning force density (F p=J c x 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.
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [3] ;  [1]
  1. Florida State Univ., Tallahassee, FL (United States)
  2. Univ. of Wisconsin-Madison, Madison, WI (United States); Gwangju Institute of Science and Technology, Gwangju (Republic of Korea)
  3. Univ. of Wisconsin-Madison, Madison, WI (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 4; Journal ID: ISSN 2045-2322
Nature Publishing Group
Research Org:
Univ. of Wisconsin-Madison, Madison, WI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
superconducting properties and materials; surfaces; interfaces and thin films
OSTI Identifier: