Critical fields and flux penetration pattern in anisotropic type II superconductors

Abstract

Calculations are presented of the upper critical field Hc2, the surface nucleation field Hc3, the slope of the magnetization curve and the free energy near Hc2 and the lower critical field Hc1. The free energy of the vortex lattice in which the flux penetrates a bulk type II superconductor depends on the orientation of the lattice relative to the principal axes of the Ginzburg effective mass tensor. The explicit form of this orientation effect is given only for a mass tensor with nearly equal principal values. The remaining results can be summarized in the statement that the parameter κ is anisotropic.