Transport and tunneling measurements of quench-condensed Bi films

We report on transport and tunneling studies of thin amorphous quench-condensed Bi.97Tl.03 samples deposited onto clean insulating substrates. The results extend into a previously unreported regime of normal sample resistances of 300-10,000 Ω. For all but the thinnest samples, measurements of the ratio of the superconducting energy gap to the superconducting transition temperature are in good agreement with previous measurements on very thick films. Tunneling measurements in the presence of small perpendicular magnetic fields are consistent with previous conclusions regarding inhomogeneities in similarly prepared samples.