ANOMALOUS RESISTANCE BEHAVIOR IN THE SUPERCONDUCTING FLUCTUATION REGION OF THIN ALUMINUM FILMS

An increase of the electrical resistance with decreasing temperature in the superconducting fluctuation region close above the transition temperature T(c) was observed in thin Al films with a thickness between 13 nm and 40 nm. The magnitude of the resistance enhancement depends on the film thickness and on the mean free path of the Al films. The anomaly appears to be due to an interaction between superconducting fluctuations and conduction electrons. The maximal resistance increase of about five percent of the measured normal resistance at 4.2 K occurs in films with a thickness of 25 nm and a mean free path of 150 nm. The increase of the resistance is quenched by a magnetic field.