Vortex liquid properties in optimally doped and oxygen-deficient YBa2Cu3O7-delta single crystals
2000 (English)In: Physica. C, Superconductivity, ISSN 0921-4534, Vol. 332, no 1-4, 86-92 p.Article in journal (Refereed) Published
The electrical anisotropy, gamma = (m(c)/m(ab))(1/2), can easily be varied by changing the oxygen content in single crystals of YBa2Cu3O7-delta (YBCO); thus making this system useful as a test system For vortex dynamics in high-temperature superconductors (HTSC). Here, some recent results are reviewed. Measurements of the c-axis resistivity with the magnetic field B II ab-plane is shown to be a powerful tool in studying vortex velocity correlations both parallel and perpendicular to the applied field. In optimally doped crystals, we iind evidence that the in-plane vortex lattice melts at T-m into a disentangled vortex liquid, which looses its correlation along the c-axis at a higher temperature T-br > T-m. For weakly disordered crystals and magnetic fields B \\ c-axis, a relation between the vortex glass line and the magnetic field dependence of the characteristic energy, U*, in the pinned vortex liquid is proposed. This approach is shown to give support to our idea of describing the vortex glass resistivity in the liquid regime by a modified glass correlation Length, xi(g) = xi(0)\k(B)T/U-0 - 1\(-nu) which depends on the average pinning energy, Lr,, in the system [A. Rydh, O. Rapp, M. Andersson, Phys. Rev. Lett. 83 (1999) 1850].
Place, publisher, year, edition, pages
2000. Vol. 332, no 1-4, 86-92 p.
electrical resistivity, pinning energy, vortex liquid properties, oxygen stoichiometry, high-temperature superconductors, t-c superconductors, thin-films, untwinned yba2cu3o7-delta, consistent description, phase-transitions, magnetic-field, mixed-state, flux motion, lattice
IdentifiersURN: urn:nbn:se:kth:diva-19781DOI: 10.1016/S0921-4534(99)00649-8ISI: 000087245200017OAI: oai:DiVA.org:kth-19781DiVA: diva2:338473
QC 20100525 QC 201112052010-08-102010-08-102011-12-05Bibliographically approved