INVESTIGATION OF THE CRITICAL STATE OF SPUTTERED YBA2CU3O7-X THIN-FILMS USING A HALL PROBE

The critical state of DC-magnetron sputtered YBa2Cu3O7-x (YBCO) thin films with critical temperatures of 90 K and critical current densities well beyond 10(6) A/cm2 was investigated after magnetization with a magnetic field of 0.14 T. The sample surface of the square-shaped YBCO films was scanned using a Hall probe and the remanent axial magnetic field in the critical state was measured at a distance of z=0.5 mm above the sample. A comparison with theoretical calculations of the axial magnetic field resulted in a good qualitative agreement of experiment and calculation. This indicates that the samples were homogeneous. Additionally, a mapping of the critical state yields a more reliable j(c)-value compared to a single local measurement without any information about the homogeneity of the sample.