Contactless characterization of melt-textured superconducting junctions using micro-Hall sensor arrays

We use spatially resolved Hall-probe magnetometry and magneto-optical imagi ng to study current-carrying properties of melt-textured high-temperature s uperconducting welds at high magnetic fields. Magneto-optical images show n o deterioration of the current-carrying properties of the sample in the pre sence of the superconducting weld. The study of the vortex dynamics near th e junction using high-resolution Hall-probe magnetometry revealed enhanced relaxation of the magnetization at the junction at high temperatures. We at tribute this behavior to an increased local concentration of defects near t he weld that, depending on the temperature range, either facilitates enhanc ed relaxation or strengthens the local pinning properties. (C) 1999 America n Institute of Physics. [S0021-8979(99)08223-7].