Levitation force from high-Tcsuperconducting thin-film disks

Anjali B. Riise, T. H. Johansen, H. Bratsberg, Michael Rudolf Koblischka, Y. Q. Shen

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27 Citations (Scopus)

Abstract

Experimental studies and theoretical modeling of the levitation force between a permanent magnet and superconducting thin film are reported. Measurements of the force Fzand magnetic stiffness κz=δFzz as functions of the magnet-superconductor separation z, show several features contrasting all previous levitation force data for bulk superconductors. In particular, the Fz(z) curves measured for decreasing and increasing separation form hysteresis loops of nearly symmetrical shape, also displaying a peak in the repulsive force branch. Recent theories for flux penetration in thin type-II superconductors in transverse magnetic fields are invoked to explain the results, which were obtained using a cylindrical Nd-Fe-B magnet and a YBa2Cu3O7-δcircular disk made by laser ablation. We derive explicit formulas for both Fzand κz, reproducing quantitatively all the features seen experimentally.

Original languageEnglish
Pages (from-to)9855-9861
Number of pages7
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume60
Issue number13
DOIs
Publication statusPublished - 1999 Jan 1
Externally publishedYes

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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