Damping of the vortex motion in superconducting Mo3Si and YBa2Cu3O7-δ
Physikalisches Institut, Lehrstuhl Experimentalphysik II,
D-72076 Tübingen, Germany
2 IBM Thomas J. Watson Research Center, P. O. Box 218, Yorktown Heights, N.Y., USA
Accepted: 22 January 1996
The damping of the vortex motion in the superconducting mixed state takes place by means of the power dissipation in the vortex core. In order to minimize the influence of flux pinning, we have performed flux flow experiments at high vortex velocities. We compare the temperature-dependent behaviour of the vortex core for a dirty low-Tc material with a high-Tc cuprate. The theoretical background was given by Larkin and Ovchinnikov, which extended the Bardeen-Stephen model taking into account nonequilibrium effects. For the low-Tc superconductor amorphous , we find that the core resistivity is equal to the normal-state value , and only weakly temperature dependent. In the cuprate decreases with decreasing temperature. The moderately clean limit and possibly node lines in -space of the order parameter appear to have a strong influence.
PACS: 74.25.Fy – Transport properties (electric and thermal conductivity, thermoelectric effects, etc.) / 74.60.Ge – Flux pinning, flux creep, and flux-line lattice dynamics / 74.80.Bj – Granular, melt-textured, and amorphous superconductors; powders
© EDP Sciences, 1996