Europhys. Lett.
Volume 68, Number 4, November 2004
Page(s) 571 - 576
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 27 October 2004
Europhys. Lett., 68 (4), pp. 571-576 (2004)
DOI: 10.1209/epl/i2004-10236-0

Critical current-voltage scaling of heavy-ion-irradiated $\chem{Bi_2Sr_2CaCu_2O_{8+\delta}}$ and $\chem{(K,Ba)BiO_3}$ superconductors

A. Ruyter1, V. Hardy2, N. H. Hong1 and L. Ammor1

1  Laboratoire LEMA, UMR 6157 CNRS-CEA, Université F. Rabelais Parc de Grandmont, 37200 Tours, France
2  Laboratoire CRISMAT, CNRS UMR 6508, ENSICAEN 6 Bd du Maréchal Juin, 14050 Caen, France

received 3 June 2004; accepted in final form 21 September 2004
published online 27 October 2004

Current-voltage characteristics were investigated in highly anisotropic $\chem{Bi_2Sr_2CaCu_2O_{8+\delta}}$, $\chem{Bi_{1.8}Pb_{0.2}Sr_2CaCu_2O_{8+\delta}}$ and isotropic $\chem{(K,Ba)BiO_3}$ single crystals which were irradiated in the direction parallel to the c-axis. In the range of magnetic fields from $B_{\phi}/10$ to $B_{\phi}$ (where $B_{\phi}$ is the matching field), same scaling functions can be used to describe the transition in those two systems. The field- and sample-independent critical exponents, which were found to be $\nu_{\bot}=1.1\pm 0.1$, $z=5.3\pm 0.2$ using $\alpha(\equiv\nu_{\parallel}/\nu_{\bot})=2$, are in a very good agreement with numerical simulations for strongly screened vortex line interactions. Moreover, the obtained scalings are the same despite a large difference in anisotropy.

74.25.Fy - Transport properties (electric and thermal conductivity, thermoelectric effects, etc.).
74.25.Qt - Vortex lattices, flux pinning, flux creep.
74.72.Hs - Bi-based cuprates.

© EDP Sciences 2004