High resolution $^{11}$B NMR of MgB$_2$ using cryogenic magic-angle spinning

ORAL

Abstract

Static and magic-angle spinning (MAS) $^{11}$B NMR data at 4.7 T and 8.5 T have been obtained under cryogenic conditions on a diluted sample of magnesium diboride powder in the normal and superconducting state. We demonstrate that MAS NMR is possible on type-II superconductors despite the sample rotation. The data provide accurate information on the magnetic shift variation and longitudinal relaxation data down to a temperature of 8 K, with a resolution improvement over the entire temperature range. The onset of superconductivity is unaffected by the sample rotation, as revealed by a steep variation of the magnetic shift just below the critical temperature.

*Appeared in JCP 137, 114201, http://dx.doi.org/10.1063/1.4751476

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Authors

  • Raivo Stern

    • National Institute of Chemical Physics and Biophysics, Tallinn-12618, Estonia
    • National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
    • National Institute of Chemical Physics and Biophysics, Tallinn, Estonia

  • Peter Beckett

    • School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK

  • Mark S. Denning

    • School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK

  • Ivo Heinmaa

    • National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia

  • Mukesh C. Dimri

    • National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia

  • Edward A. Young

    • Institute of Cryogenics, School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ, UK

  • Marina Carravetta

    • School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK