Critical behavior of vortices in epitaxial Tl-2201 films at zero external field
Artikel i vetenskaplig tidskrift, 2004

The resistive transition and current–voltage characteristics of a Tl-2201 superconducting microbridge are measured close to the critical temperature in zero external magnetic field. The dissipation mechanism is studied by analyzing dV/dI and power dissipation P(= IV) as functions of transport current. The Jc–T curves exhibit three distinct types of behavior depending on temperature. In the low temperature regime, the critical current density is proportional to (1 – T/Tc). At intermediate temperatures, thermally activated flux creep dominates and Jc is proportional to 1 – n(T/Tc) – m(T/Tc)2. In the high temperature regime, Jc is equal to the G–L depairing current. The depinning current, Jc1, is determined, taking into account thermally activated flux motion and flux motion induced by the transport current. Jc1 depends linearly on temperature and vanishes at 82 K, Jc1 = Jc1(0) (1 – T/Tc1).

resistive transition

single-crystal laalo3

vortex-glass transition




current-voltage characteristics


high-temperature superconductors



H.Q. Chen

Universitetet i Oslo

Lars-Gunnar Johansson

Göteborgs universitet

Zdravko Ivanov

Chalmers University of Technology

Physica Status Solidi (B): Basic Research

0370-1972 (ISSN) 1521-3951 (eISSN)

Vol. 241 15 3556-3562


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