Observation of low-frequency electrical current oscillations in ferrocene sample with adsorbed 2-propanol vapor

Abstract

Low-frequency oscillations in electrical current (dark) as a function of time were observed, in the temperature range where unusual/anomalous change in electrical conductivity with temperature was noticed in the samples of ferrocene with physically adsorbed 2-propanol vapor (at 40 torr pressure) molecules as impurities in a sandwich type of cell configuration. With the increasing bias voltage across the electrodes, at a constant sample cell temperature, increase in both the time interval between the two consecutive current peaks (i.e. decrease in frequency of current oscillations) and current peak height was noticed. The current-voltage characteristics behavior of ferrocene with adsorbed 2-propanol vapor has indicated the ohmic nature of conductivity. Existing theories of current oscillations in semiconductors have failed to explain the observed low-frequency current oscillations in this organometallic semiconductor. Such current oscillations are possibly associated with some kind of time dependent phase changes in the ferrocene- (2-propanol) vapor system/surface layer.