| Popis: |
We report the fabrication and operation of YBCO thin film DC SQUIDs on Sapphire substrates. The film are prepared by the sequential deposition of Cu, Y2O3, BaF2, with post annealing, and are about 1μm thick. The film are patterned by a conventional photolithographic method on the Cu layer, before the deposition of Y2O3 and BaF2. The critical temperature of the devices is higher than 80 K, and the product of their estimated inductances with the corresponding critical currents is much larger than Φ0. The SQUIDs have been measured in the resistive mode by a DC technique, with an external magnetic field applied by a small coil. We observed modulation of the voltage on the SQUIDs with the applied flux of the order of 20 μV, with an hysteretic behaviour of the V−Φ curves. |
