Electrical switching in bulk samples of 0.15As-0.12Ge-0.73Te glass

Abstract

Switching in bulk samples of 0.15As--0.12Ge--0.73Te glass is found to be caused predominantly by the thermal switching mechanism for near threshold applied voltages. Switching also occurred by the thermal mechanism even for applied voltages an order of magnitude above the threshold voltage of the sample. In order to investigate a switching event in this glass sample, a constant voltage pulse was applied to the sample and the delay time and the electrical energy input to the sample during the delay time measured. A log--log plot of the energy input to the sample during a delay time of 1.00 s as a function of the electrode spacing on the sample's surface was found to have a slope of approximately 1.6. For the theoretical study of the thermal switching mechanism, a one-dimensional calculation of the heat balance equation with radial heat flow was made and the results of the calculation followed the same trends as the experimental data. The large scatter in parts of the data and the increase in the average resistance of the sample for a switching event with near threshold applied voltages could not be explained by the thermal switching mechanism. These effects could be a manifestation of themore » structural changes which probably occur in the sample as a result of the high temperatures present at the moment of switching. 33 fig.« less