Effect of heavy-ion irradiation on transport properties of YBa/sub 2/Cu/sub 3/O/sub x/ films

We have investigated the effect of heavy-ion irradiation on the transport properties of YBa/sub 2/Cu/sub 3/O/sub x/ thin films. Parallel columnar defects to the c axis and crossed columnar defects were introduced into films by heavy-ion irradiation with dose equivalent to 1 or 2 T vortex density. The electrical transport properties including resistivity, critical current density, and the Hall resistivity were measured as a function of temperature, applied magnetic field, and fluence. The irreversibility line defined as an onset of dissipation progressively shifted to higher temperature with increasing dosage and showed its dependence on inclination angle. Critical current also showed a clear enhancement compared to the unirradiated samples. The Hall scaling behavior and the Hall conductivity were modified after heavy-ion irradiation.