Vortex dynamics in ferromagnetic / high T$_{c}$ superconducting heterostructures

ORAL

Abstract

In this work we explore the influence of the ferromagnetic landscape generated by magnetic phase separation in manganites on the vortex pinning of HTS/FM heterostructures. We have grown Gd$_{2/3}$Ca$_{1/3}$MnO$_{3 }$(GCMO), Y$_{2/3}$Ca$_{1/3}$MnO$_{3 }$(YCMO) and YBCO films, as well as GCMO/YBCO and YCMO/YBCO bilayers by Pulsed Laser Deposition. GCMO is a ferrimagnetic material with Curie temperature of $\sim $ 80 K and a compensation temperature of 15 K, whereas YCMO is ferromagnetic with Curie temperature $\sim $ 80 K. In both materials the saturation magnetization is smaller than the value expected from ferrimagnetic and ferromagnetic order, suggesting phase separation with small ferromagnetic domains. The magnetic domain size as a function of temperature for the magnetic films was investigated using magnetic force microscopy (MFM). We will present a comparison of the vortex pinning and dynamics in the YBCO single layers and the GCMO/YBCO and YCMO/YBCO bilayers that allows us to identify the temperature and field regimes where magnetic pinning is effective.

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Authors

  • N. Haberkorn

    • Los Alamos National Laboratory, Los Alamos, NM, USA
    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • J. Kim

    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • M. Miura

    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • B. Maiorov

    • Los Alamos National Laboratory, Los Alamos, NM, USA
    • Los Alamos National Laboratory, NM 87544
    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • P. Dowden

    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • L. Civale

    • Los Alamos National Laboratory, Los Alamos, NM, USA
    • Los Alamos National Laboratory, NM 87544
    • Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA