Abstract
Amorphous Ag-Te films were obtained by diffusing Ag atoms at 203K from an already deposited crystalline Ag film into the oncoming Te atom vapor or by diffusing Ag atoms into an amorphous Te film. When the Ag film is deposited first, monitoring in-situ the resistance of the Ag film while depositing Te establishes unambiguously that it is Ag that diffuses into Te. The Ag diffusion rate at 300K is 4x105 Å2 sec-1 with an activation energy of 0.3 eV. The temperature of 203K is high enough to allow sufficiently rapid diffusion and low enough to result in an amorphous film. All amorphous Ag-Te films display variable range hopping (resistivity proportional to exp(T0/T)¼)