Contribution of plastic interactions to the pinning energies in a deformed flux-line lattice in high-Tc superconductors

The existence of strong pinning centers in the form of amorphous defects in a deformed Bur-line lattice (FLL) considerably modifies the free energy of the vortices in the mixed state. In particular, the contribution of the plastic interactions to the pinning energies as the dislocation fields modify the elastic manifold of the lattice is examined. The question whether the logarithmic dependence of U(J) on the current density is determined by the pinning potential with a long range tail or by disorder is investigated. In this paper we provide an answer to the above question that an important component to the distribution of pinning potentials in the two-dimensional planes arises from disorder in the form of plastic interaction between dislocation fields and random pinning sites in the superconductor. Furthermore, the effect of the plastic deformations as the magnetic field increases is to change the pinning mechanism, therefore, modifying the shape of the pinning potential. (C) 1998 Published by Elsevier Science B.V.