Correlated enhancement of H$_{c2}$ and J$_{c}$ in carbon nanotube-doped MgB$_{2}$.

ORAL

Abstract

We achieved simultaneous enhancement of upper critical magnetic field, H$_{c2}$, and critical current density, J$_{c}$, by doping polycrystalline samples of MgB$_{2}$ with double-wall carbon nanotubes (DWCNT), a source of atomic carbon. The optimum DWCNT content from the point of view of the J$_{c}$ is in the range 2.5-10{\%} at depending on field and temperature. Record values for H$_{c2}$ (4K) = 41.9 T (with extrapolated H$_{c2}$(0) $\approx $ 44.4 T) are reached in a bulk sample with 10{\%} at DWCNT content. The measured H$_{c2}$ vs T in all samples are successfully~described using a theoretical model for a two-gap superconductor in the dirty limit first proposed by Gurevich \textit{et al}.

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Authors

  • M. Jaime

    National High Magnetic Field Laboratory, Los Alamos National Laboratory, MPA-NHMFL, LANL, NHMFL-LANL, National High Magnetic Field Laboratory, LANL, Los Alamos, NM, MPA-NHMFL, LANL, Los Alamos, NM 87544

  • A. Serquis

    CAB, Bariloche, Argentina

  • G. Serrano

    CAB, Bariloche, Argentina

  • S. Moreno

    CAB, Bariloche, Argentina

  • L. Civale

    Superconductivity Technology Center, LANL, Los Alamos, NM, MPA-STC, LANL, Los Alamos, NM 87544

  • B. Maiorov

    Superconductivity Technology Center, LANL, Los Alamos, NM, MPA-STC, LANL, Los Alamos, NM 87544

  • F. Balakirev

    National High Magnetic Field Laboratory, LANL, Los Alamos, NM, National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545, USA, MPA-NHMFL, LANL, Los Alamos, NM 87544