MIXED-STATE HALL-EFFECT IN HGBA2CACU2O6-FILMS WITH COLUMNAR DEFECTS(DELTA THIN)

The mixed state Hall effect has been studied in high quality HgBa2CaCu 2O6+delta thin films while the pinning strength is modified by the irr addition of columnar defects. It has been shown that the pinning stren gth can be significantly improved by columnar defects. The sign revers al in Hall resistivity is found to be nearly independent of pinning wh ile the scaling behavior between Hall resistivity (rho(xy)) and longit udinal resistivity (rho(xx)) is influenced by pinning. The exponent be ta in the scaling law rho(xy) similar to rho(xy)(beta) decrease from 1 .8 +/- 0.1 to 1.5 +/- 0.1 as pinning is enhanced. This results suggest that the sign reversal and the scaling are unrelated, and pinning is not the mechanism of the sign reversal.