Annealing of defects after irradiation of YBCO single crystals with fast electrons

摘要

The effect of annealing on the conductivity of optimally doped YBa(2)Cu(3)O(7-delta )single crystals irradiated with fast electrons is investigated. The variation of width of the superconducting transition with increase of the irradiation dose and in the course of annealing is associated with the evolution of the sample inhomogeneity. A recovery of the critical temperature T-c after annealing to some intermediate value between those in the initial and irradiated states is observed. This recovery of T-c is accompanied by a substantial narrowing of the superconducting transition whose width nicely matches that in the non-irradiated state. The observed transition narrowing is attributed to an improvement of the sample homogeneity in consequence of the diffusion-induced growth and eventual coalescence of superconducting domains. In addition, the complete recovery of the normal conductivity after annealing points to a reversible change of parameters of the charge carriers scattering on phonons and defects.