Nontrivial effects of point-like disorder on critical fields and pinning in s± superconductors

ORAL

Abstract

In most superconductors non-magnetic point-like defects enhance pinning and upper critical field. However, in s± superconductors, for example iron-based compounds, point-like disorder influences not only intra-band potential scattering, but also inter-band pair-breaking scattering rates. The latter leads to suppression of Tc, Hc2 and the condensation energy. The balance between these opposite effects leads to an increase of (dHc2/dT)T=Tc slope with the decrease of Tc, opposite to what is observed as a function of doping. Even more unusual, it may also lead to a suppression of strong pinning believed to be responsible for a sharp peak in magnetization near H=0. In our experiments controlled disorder was induced by 2.5 MeV electron irradiation.

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Presenters

  • Ruslan Prozorov

    Ames Laboratory US DOE, Ames, Iowa, Iowa State University, Ames Laboratory, Iowa State University, Ames Laboratory, Ames Laboratory and Iowa state University, USA, Ames Laboratory and Iowa State University, Ames, IA, USA, Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA

Authors

  • Ruslan Prozorov

    Ames Laboratory US DOE, Ames, Iowa, Iowa State University, Ames Laboratory, Iowa State University, Ames Laboratory, Ames Laboratory and Iowa state University, USA, Ames Laboratory and Iowa State University, Ames, IA, USA, Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA

  • Marcin Konczykowski

    Laboratoire des Solides Irradiés, École Polytechnique, F-91128 Palaiseau, France, Ecole Polytechnique, Ecole Polytechnique, Palaiseau, France, LSI, Ecole Polytechnique, Laboratoire des Solides Irradies, Ecole Polytechnique

  • Vladimir G. Kogan

    Ames Laboratory, Iowa State University, Ames Laboratory

  • Makariy Tanatar

    Ames Laboratory, Ames Laboratory US DOE, Ames, Iowa, Ames Laboratory and Iowa State University, Ames, IA, USA, Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA