Magnetic force microscopy study of the penetration depth in MgB$_{2}$ thin films

ORAL

Abstract

We performed magnetic force microscopy (MFM) investigations of superconducting vortices in thin films of MgB$_{2}$. Our MFM instrument has the capability of scanning multiple samples. Prior to imaging vortices in MgB$_{2}$, vortex imaging in a Nb thin film was performed to characterize the cantilever's tip. This procedure allows extraction of the penetration depth with only one fitting parameter. Images of two MgB$_{2}$ films with different thickness were taken as a function of temperature, together with periodic checks of the condition of the magnetic tip via imaging of vortices in the Nb reference sample, during a single cooldown. The temperature dependent penetration depth determined by MFM will be compared to that obtained via SQUID magnetometry on the same samples.

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Authors

  • Jeehoon Kim

  • Leonardo Civale

    • MPA Division, Los Alamos National Laboratory

  • Evgueni Nazaretski

    • Brookhaven National Laboratory, Upton, NY

  • Nestor Haberkorn

    • MPA Division, Los Alamos National Laboratory

  • Josh Thibodaux

  • Ilya Vekhter

    • Dept of Physics and Astronomy, Louisiana State University

  • Brian Moeckly

    • Superconductor Technologies, Inc., Santa Barbara

  • Joe D. Thompson

  • Roman Movshovich

    • MPA Division, Los Alamos National Laboratory