Reversible monopolar switching in vanadium-tellurite glass threshold devices

Abstract

Monopolar threshold switching, having a threshold voltage lower than for bipolar switching, has been observed in vanadium-tellurite glasses. By changing the external circuit conditions, a transition from a monopolar to a bipolar mode of operation and vice versa is feasible. This unusual mode of operation demonstrates a memory ability, related to the direction of the electric field. The monostable memory effect is a fully reversible and repeatable operation. A mechanism is suggested to explain both the monopolar and the bipolar switching. The model has as its basis the variation of subcritical nuclei concentration from a phase with metallic conduction under the action of an electric field. An experimental dependence is found between the monopolar threshold and the series resistance of the external circuit. The physical meaning of the constant in this dependence is revealed in terms of the mechanism mentioned above.