Characterization of high-T_c superconducting tapes using Hall sensors

A new inductive method for the characterization of high-Tc superconducting tapes is proposed and tested. It is based on the measurement of the magnetic field profile produced by induced screening currents in a tape. The measurements are carried out using a movable miniature Hall sensor connected to a special electric circuit, allowing measurements of magnetic fields in the μT range (field due to tape magnetization) in applied fields in the mT range. The method can be used as a quick routine for the determination of transport critical densities of high-Tc superconducting tapes. Further, it effectively reveals macroscopic sample inhomogeneities resulting in a decrease in local transport current density. The method is demonstrated with experiments in Bi-2212/Ag and Bi-223/Ag tapes.