Possible robust insulator-superconductor transition on solid inert gas andother substrates - art. no. 104502

We present observations of the insulator-superconductor transition in ultra thin films of Bi on amorphous quartz, quartz coated with Ge, and solid xeno n condensed on quartz. The relative permeability epsilon (r) ranges from 1. 5 for Xe to 15 for Ge. Though we find screening effects as expected, the I- S transition is robust, and unmodified by the substrate. The resistance sep aratrix is found to be close to h/4e(2) and the crossover thickness close t o 25 Angstrom for all substrates. I-V studies and Aslamazov-Larkin analyses indicate superconductivity is inhomogeneous. The transition can be underst ood in terms of a percolation model.