skip to main content


Title: Effects of proton irradiation on flux-pinning properties of underdoped Ba(Fe 0.96Co 0.04) 2As 2 pnictide superconductor

We study the effect of proton irradiation on Ba(Fe 0.96Co 0.04) 2As 2 superconducting single crystals from combined magnetisation and magnetoresistivity measurements. The study allows the extraction of the values of the apparent pinning energy U 0 of the samples prior to and after irradiation, as well as comparison of the values of U 0 obtained from the flux-flow reversible region with those from the flux-creep irreversible region. Irradiation reduces T c modestly, but significantly reduces U 0 in both regimes: the critical current density J c is modified, most strikingly by the disappearance of the second magnetisation peak after irradiation. Analysis of the functional form of the pinning force and of the temperature dependence of J c for zero field, indicates that proton irradiation in this case has not changed the pinning regime, but has introduced a high density of shallow point-like defects. Lastly, by considering a model that takes into account the effect of disorder on the irreversibility line, the data suggests that irradiation produced a considerable reduction in the average effective disorder overall, consistent with the changes observed in U 0 and J c.
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [2] ; ORCiD logo [1]
  1. Univ. Federal do Rio de Janeiro, Rio de Janeiro (Brazil)
  2. Imperial College, London (United Kingdom)
  3. Instituto Nacional de Metrologia Qualidade e Tecnologia, Duque de Caxias (Brazil)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Alloys and Compounds
Additional Journal Information:
Journal Volume: 694; Journal Issue: C; Journal ID: ISSN 0925-8388
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; pnictides; proton irradiation; superconducting critical current; flux-pinning
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1397591