%0 Journal Article %T Possible robust insulator-superconductor transition on solid inert gas and other substrates %A K. Das Gupta %A G. Sambandamurthy %A Swati S. Soman %A N. Chandrasekhar %J Physics %D 2000 %I arXiv %R 10.1103/PhysRevB.63.104502 %X We present observations of the insulator-superconductor transition in ultrathin films of Bi on amorphous quartz, quartz coated with Ge, and for the first time, solid xenon 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 separatrix is found to be close to h/4e^2 and the crossover thickness close to $\rm 25 \AA$ for all substrates. I-V studies and Aslamazov-Larkin analyses indicate superconductivity is inhomogeneous. The transition can be understood in terms of a percolation model. %U http://arxiv.org/abs/cond-mat/0011197v1