Superconducting fluctuation effects in amorphous-bismuth thin films in the presence of a perpendicular magnetic field

The resistive transition of amorphous-Bi thin films ranging from 100 to 2900 Å thick was measured in perpendicular magnetic fields to 6000 G. The results were compared with a form of the Aslamazov-Larkin theory modified to account for the presence of a magnetic field. Results were in agreement with theory for $H_{\perp }\lesssim 1000$ G; at higher fields the effects of superconducting fluctuations were overshadowed by flux-flow resistance. From the measurements, the Ginzburg-Landau coherence-length constant was determined to be $\eta =(72\mathrm{}\pm 5)$ Å. No evidence was seen for a contribution from the Maki-Thompson fluctuation mechanism.