Hysteresis in Superconductors. I. Flux Trapping in Low- and High-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>κ</mml:mi></mml:math>Materials

Abstract

Flux-trapping properties of type-II superconductors are described. A linear relationship between the remnant magnetization and the internal field is observed in the low-$\ensuremath{\kappa}$ superconductors but not in ${\mathrm{Nb}}_{3}$Sn and ${\mathrm{Nb}}_{3}$Zr. It was found that the linear relationship and the associated slopes are to a large extent independent of much of the bulk and are related to surface currents. In addition, the linear relationships are observed only in low-$\ensuremath{\kappa}$ superconductors that exhibit appreciable diamagnetic behavior.