TEMPERATURE AND MAGNETIC-FIELD DEPENDENCE OF THE HALL-EFFECT IN THE MIXED STATE OF HOBA2CU3O7-X HTCS THIN-FILMS

The Hall effect of high-temperature superconducting (HTCS) Ho-Ba-Cu-O thin films has been measured in applied magnetic fields up to 90 kOe in the region close to the superconducting onset temperature. The 90 kOe Hall coefficient R(H) decreases to zero from the superconducting onset temperature in a way that closely resembles the behaviour of the resistivity superconducting transition in an applied magnetic field. The magnetic field dependence of the Hall voltage V(H) in the mixed state is strongly nonlinear, showing certain features that suggests that vortex deppining mechanisms play an important role in the Hall effect behaviour. A log-log plot applied magnetic field vs. temperature for this "activation" process exhibits the same power law behaviour that is observed in the measurement of the resistivity with an applied magnetic field.