The electrical conductivity of thin metallic films I—Rubidium on pyrex glass surfaces

This paper describes measurements of the resistivity of thin films of rubidium, deposited on cooled pyrex surfaces by a method which allows the use of the conditions of purity and high vacuum possible with modern technique. In this work, by vigorous heat treatment in high vacua, clean pyrex surfaces have been obtained on which stable and coherent films as thin as 40 A. have been produced. Conductivities have been obtained with a number of atoms on the surface corresponding to less than the number contained in a monatomic layer of rubidium; moreover, the approach of thicker films to the resistivity of the bulk metal is in agreement with that calculated from a simple theory which takes account of the fact that the film thickness is less than the normal electronic mean free path in the bulk metal.