Resistivity induced by electron-grain boundary scattering on thin gold films deposited on mica substrates under high vacuum

We report measurements of the room temperature resistivity and of the grain size distribution on a family of gold films deposited onto mica substrates under high vacuum. The films are of the same thickness (100 nm $\pm$ 10{\%}), deposited at the same rate (3 nm/min), varying both the temperature of the substrate and the annealing temperature (if any) between --170 $^{\circ}$C and +270 $^{\circ}$C. The grain distribution was measured with a Scanning Tunneling Microscope. The average grain size decreases from approximately 200 nm to a few nm, when the temperature of the substrate decreases from +270 $^{\circ}$C to --170 $^{\circ}$C during evaporation. The monotonic decrease in grain size leads to a monotonic increase in resistivity of almost one order of magnitude. The resistivity of the film evaporated with the substrate held at +270 $^{\circ}$C and annealed for one hour at +270 $^{\circ}$C after evaporation, exhibits a room temperature resistivity only a few percent larger than crystalline gold. Research funded by FONDECYT 1040723.