Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-29T09:50:43.175Z Has data issue: false hasContentIssue false

Time Domain Response of Electrical Ceramics Micro to Megaseconds

Published online by Cambridge University Press:  10 February 2011

F. A. Modine*
Affiliation:
Solid State Division, Oak Ridge National laboratory, Oak Ridge, TN 37831–6030
Get access

Abstract

The electrical properties of ceramics can be measured in either the time domain or in the frequency domain. But for electrically nonlinear ceramics such as varistors, time-domain measurements provide insights that are different and more relevant to material performance as well as being more physically incisive. This article focuses specifically on the electrical properties of ZnO varistors, but much of it is of relevance for other materials, in particular those materials with grain-boundary barriers and disordered ceramics or glasses. The interpretation of electrical measurements in the time domain is profoundly influenced by such practical matters as source impedance and waveform characteristics. Experimental results are presented for both high and low source impedance relative to that of a test varistor, and the difference in experimental difficulty and ease of interpretation is described. Time-domain measurements of capacitance and of the inductive response of varistors to large, fast electrical pulses are presented and their implications for varistor theory are given. Experimental evidence is given of short- and long-term memory in varistors. These memory phenomena are ascribed respectively to the life time of holes that become trapped in barriers and to polarization currents originating from deep electron traps. Polarization current measurements are presented for a wide range of time and temperature. The power-law time dependence and “universal” behavior of these currents is discussed. The exponent that describes the power law behavior is seen to change with temperature, and the change is interpreted as a double transition from diffusive to dispersive transport that originates with current from two different electron traps.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Modine, F. A. and Wheeler, R. B., J. Appl. Phys. 61, 3093 (1987).Google Scholar
2. Mahan, G. D., Levinson, L. M., and Philipp, H. R., J. Appl. Phys. 50, 2799 (1979).Google Scholar
3. Pike, G. E., Mater. Res. Soc. Proc. 5, 369 (1982).Google Scholar
4. Pike, G. E., Kurtz, S. R., Gourley, P. L., Philipp, H. R., and Levinson, L. M., J. Appl. Phys. 57, 5521 (1985).Google Scholar
5. Rossinelli, M., Blatter, G., and Greuter, F., British Ceram. Proc. 36, 1 (1985).Google Scholar
6. Pike, G. E., Phys. Rev. B 30, 795 (1984).Google Scholar
7. Blatter, G. and Greuter, F., Phys. Rev. B 33, 3952 (1986).Google Scholar
8. Blatter, G. and Greuter, F., Phys. Rev. B 34, 8555 (1986).Google Scholar
9. Green, M. A. and Shewchun, J., Solid State Electron. 16, 1141 (1973).Google Scholar
10. Eda, K., J. Appl. Phys. 50, 4436 (1979).Google Scholar
11. Modine, F. A. and Wheeler, R. B., J. Appl. Phys. 67, 6560 (1990).Google Scholar
12. Modine, F. A., Wheeler, R. B., Shim, Y., and Cordaro, J. F., J. Appl. Phys. 66, 5608 (1989).Google Scholar
13. Modine, F. A., Major, R. W., Choi, S. I., Bergman, L. B., and Silver, M. N., J. Appl. Phys. 68, 339 (1990).Google Scholar
14. Major, R. W., Werner, A. E., Wilson, C. B., and Modine, F. A., J. Appl. Phys. 76, 7367 (1990).Google Scholar
15. Alim, M. A., J. Appl. Phys. 78, 4776 (1995).Google Scholar
16. Seager, C. H. and Pike, G. E., Appl. Phys. Lett. 40, 471 (1982).Google Scholar
17. Jonscher, A.K., Dielectric Relaxation in Solids, (Chelsea Dielectrics, London, 1983).Google Scholar
18. Scher, H., Shlesinger, M. F., and Bender, J. T., Phys. Today 26 (Jan. 1991).Google Scholar