DISORDER-INDUCED REDUCTION OF THE ANOMALOUS HALL VOLTAGE IN PROTON-IRRADIATED AND AG21-ION-IRRADIATED TL2BA2CACU2O8 EPITAXIAL-FILMS()

The effects of structural disorder introduced by proton and heavy-ion irradiation on the mixed-state Hall resistivity (rho(xy)) of Tl2Ba2CaC u2O8 films are reported. The rho(xy) attains a peak negative value at a temperature T where the vortex mobility is a rapidly varying functi on of temperature. At T it also shows a universal inverse scaling wit h the normal-state resistivity of the material, which increases on irr adiation. Our data suggest that a stronger downstream contribution to vortex velocity from the drift of the normal carriers in the core, dic tates the sign of the Hall voltage as the overall carrier concentratio n in the materials is reduced by irradiation.