ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Following an earlier study on the temperature dependence of the resistive component of the leakage current of a ZnO varistor, a detailed study has been undertaken in this paper to compare the temperature dependence of the resistive (IR), capacitive (IC), and total (IT) leakage currents between unannealed and 600 °C annealed samples. It is shown that, as before, an Arrhenius plot of IC and IR versus temperature can best be represented by a break in the plot comprising a high-temperature regime (125–165°C) with a high activation energy and a low-temperature regime (30–100 °C with a low activation energy. The activation energies of IR-T curves are generally higher than those of IC-T curves in both temperatures regimes. Upon annealing at the critical temperature of 600 °C, the activation energy changes for both current components, accompanied by increased stability of the varistor. For IR, the activation energy becomes higher in the low-temperature regime in agreement with previous observation, and for IC, it becomes lower in the higher-temperature regime. The relative contributions of these two current components on total current are also different in the two temperature regimes. In the low-temperature regime, the total current is mostly capacitive, and in the high-temperature regime, it is mostly resistive. The varistor is thus prone to more Joule heating in the high-temperature regime than in the low-temperature regime.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.346767
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