Hall Effect and Transverse Voltages in Type-II Superconductors in the Mixed State

Abstract

We have recently reported (1) the observation of “dip” effects in the Hall voltage and Hall angle of a type-II superconductor (Nb-l%Zr) which are analogous in some respects to the well-known dip effect in the longitudinal voltage exhibited by many superconductors in the mixed state (2). Such effects, which are sensitive to the applied magnetic field and current density, have been attributed to manifestations of the superconducting state in which vortex motion is influenced by surface or bulk defects of the specimens (3,4). Thus it should be possible to obtain information concerning vortex-defect and vortex-vortex interactions from the study of these effects. We shall describe experiments on ribbons of Nb-l%Zr which have been cold-rolled to a thickness of 19 µm which demonstrate (1) the effect of defects which reduce the Hall angle and may produce a dip effect in both the Hall voltage V H and Hall angle θ H as well as the longitudinal voltage V L , and (2) the effect of aligned lattice or surface imperfections, which introduce transverse voltages which are not Hall voltages.