Interplay between two families of columnar defects in Bi-2212 single crystals

Abstract

Two families of perpendicular columnar defects, titled by +45° and −45° from the c axis, have been introduced in Bi-2212 single crystals by heavy ion irradiation. Using vector magnetometry, the maximum of pinning efficiency is observed when the magnetic field is applied along the defect mid-direction. Furthermore, the peak of current densities observed in the case of parallel defects along the defect direction is destroyed after the introduction of the second family of defects. The creep processes do not seem to be reduced after the introduction of the second family of defects, contrary to what is expected for these splayed defects.