Influence of the interface on the electronic channel switching of a Fe–Ag thin film on a Si substrate

FexAg100−x granular thin films, being 20<x<70, were prepared by pulsed laser deposition. The thermal evolution of the electric resistance shows a dramatic drop in the range of 200<T<300 K, completely reversible with temperature and associated to a current switching between the granular thin film and its Si substrate. High resolution transmission electron microscopy measurements have revealed an amorphous interface between the thin film and the substrate, and x-ray absorption spectroscopy studies have demonstrated an electronic localization associated to the Fe atoms in this interface, which is intrinsically responsible for the current switching.