Hall Effect in YBa2Cu3Ox Thin Films and Contact Misalignment

Abstract

The sign of the Hall effect provides critical transport information both for the normal state and superconducting state of High Temperature Superconductors. For Hall effect measurements in thin films, a contact misalignment of only a few micrometers produces a significant longitudinal voltage in addition to the transverse Hall voltage. This misalignment voltage is usually cancelled by reversing the current and magnetic field. However problems may arise for normal state transport in anisotropic materials and vortex flow in the mixed state. In this paper the effect of misalignment of the Hall sidearm electrodes is considered in detail for the case of c-axis oriented YBa2Cu3Ox thin films. The longitudinal voltage produced by the sidearm displacement is used with the Hall voltage to determine a localized Hall tangent. For the normal state this value is found to be in good agreement with the average Hall tangent for the whole film. Differences found between the localized and average Hall tangents for the transition region suggests a method for detecting the motion of single vortices.