Eur. Phys. J. B 33, 255-264 (2003)
https://doi.org/10.1140/epjb/e2003-00164-9

About magnetic relaxation of partially penetrated screening current in superconductors with various models of flux creep

Russian Research Center “Kurchatov Institute”, Kurchatov Square, 123182 Moscow, Russia

Corresponding author: ^a vromanovskii@netscape.net

Received: 30 August 2002
Revised: 10 February 2003
Published online: 20 June 2003

Abstract

Magnetic relaxation of the partially penetrated screening current during flux creep has been studied. A theoretical analysis was based on the macroscopic description of the flux creep using the power and exponential equations for current-voltage characteristics of superconductors. The analytical flux-creep solutions were written and compared with numerical simulations of corresponding problems. Equations describing the relaxation of the electromagnetic field, magnetic moment, moving penetration boundary are derived. It is shown that peculiarities of relaxation phenomena are determined by dynamics of the electric field on the surface of the superconductor. The performed analysis allows to formulate nontrivial conjugation conditions that take place on moving boundary of screening current. In accordance with these conditions the electromagnetic field induced inside a superconductor by external perturbations smoothly approaches its undisturbed values. The essential role of the low electric field area of current-voltage characteristics in the flux relaxation and primarily in high-temperature superconductors is shown.