Negative differential resistance in thin metal films with a cadmium arachidate overlayer

Voltage controlled negative differential resistance and electron emission are known to occur in thin gold films subsequent to the application of a forming voltage. A post forming deposition of an overlayer of cadmium arachidate using the Langmuir-Blodgett technique has been performed. The observed conduction current is significantly enhanced and the value of applied voltage at which it occurs increases; the underlying gold film shows no sign of damage. These changes in the conduction current also occur in the electron emission. It is suggested that the increased electrical conductivity of the samples is due to changes in the thermal environment of conducting filaments. The change in peak position can then be accounted for by considering the intrinsic film resistance and the current enhancement.