Abnormal Transverse-Field Effects in Nonideal Type 2 Superconductors. III. A Theory for an AC-Induced Decrease in the Semi-Quasistatic Magnetization Parallel to a DC Bias Field

It was suggested in our previous paper that the abnormal transverse-field effects observed in a superconducting wire in an AC magnetic field perpendicular to a transverse DC bias field originate from a kind of bending deformation of fluxoids. It was also shown that the steady behavior in magnetization could be explained quantitatively based on this mechanism with the aid of the usual critical-state model. It this paper, a phenomenological theory for the asymmetric bending deformation of fluxoids is presented to describe the non-steady phenomena in the abnormal transverse-field effects. The observed variation of the magnetization is explained well by the present theory. The influence of the asymmetric bending deformation of fluxoids on the magnetic behavior of a wire in the presence of a transport current are also discussed.