Resistance of superconducting fault current limiters based on YBa2CU3O7 thin films after quench completion

We investigated the time dependence of the resistance of superconducting fault current limiters (SFCLs) based on YBa2Cu3O7 thin films after quench completion. The 0.3 mum thick film was coated with a gold layer of 0.2 mum thickness and patterned into pairs of 1 mm wide and 26 cm long meander lines by photolithography. The SFCL was subjected to simulated AC fault currents of various peak values. The resistance of the SFCL consisted of an oscillatory component and a slow varying one. The slow varying component of the resistance increased exponentially with time after the initial rapid increase due to phase transition. The magnitude of the oscillatory component was small compared with the slow varying one. These results could be explained quantitatively with the concept of heat transfer within the film and to the surroundings. (C) 2002 Elsevier Science B.V. All rights reserved.