Evidence for Diverging Barriers in the Disordered Vortex Solid in the K,Ba BiO3 Superconducting Oxide

I. Joumard (1) , Thierry Klein (1) , J. Marcus (1)

1 LEPES - Laboratoire d'Etudes des Propriétés Electroniques des Solides

Vortex dynamics has been investigated in the cubic K, Ba BiO3 superconductor using ac susceptibility measurements on a large frequency range 0.03 Hz , v , 60 kHz . Power law diverging barriers have been obtained on both sides of the order-disorder transition line. The m exponent remains close to 5 2 (elastic creep value) in some part of the disordered phase and finally decreases at high temperature and/or high field, in good agreement with the recent plastic collective creep theory [J. Kierfeld, H. Nordborg, and V. M. Vinokur, Phys. Rev. Lett., 85, 4948 (2000)].

Domaines: Supraconductivité [cond-mat.supr-con]

I. Joumard, Thierry Klein, J. Marcus. Evidence for Diverging Barriers in the Disordered Vortex Solid in the K,Ba BiO3 Superconducting Oxide. Physical Review Letters, 2001, 87, pp.167002. ⟨10.1103/PhysRevLett.87.167002⟩. ⟨hal-00959106⟩