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Conductivity and Noise Measurements in 3D Percolative Cellular Structures

Published online by Cambridge University Press:  10 February 2011

C. Chiteme  and
D. S. McLachlan
C. Chiteme
Affiliation:
Physics Department, University of the Witwatersrand, Johannesburg, SA.
D. S. McLachlan
Affiliation:
Physics Department, University of the Witwatersrand, Johannesburg, SA.
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Abstract

Conductivity results and 1/f noise (Sav) measurements from some systems with a cellular structure (composites in which small conductor particles embed on the surface of larger and regular insulator particles) are given. The usual DC percolation parameters (φc,t & s) were obtained from fitting the results to the Percolation equations. φc values for the systems have been found to lie in the range 0.01 – 0.07, while both non-universal and close to universal values have been measured for the exponents s and t. In addition, 1/f or flicker noise results on the systems give an additional exponent ω from the relationship Sav/Vdc2 = KRω. For the systems measured so far, the exponent ω is observed to take different values ω1 close to and ω2 further away from the conductor-insulator transition, but on the conducting side (ω > ωc). The very different values (s, t & ω), obtained for the various conducting powders, in the same macroscopic structure, indicates that the way the powders distribute themselves on the insulating particles is a major factor in determining the exponents.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 500: Symposium EE – Electrically Based Microstructural Characterization II , 1997 , 357
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1. Nan, C. W., Prog. in Mat. Sci. 37, 1–116 (1993).Google Scholar
2. Abeles, B., App. Sol. Stat. Sci., vol. 6, 1–109, Acad. Press (1976).Google Scholar
3. Garland, J.C. and Tanner, D. B., AIP Conf. Proc. no. 40, p 2–416 (1977)Google Scholar
4. Malliaris, A. and Turner, D.T., J. Appl. Phys. 42, no. 2, p. 614–618 (1971).Google Scholar
5. Kusy, R.P., J. Appl. Phys. 48, no. 12, 5301–05 (1977).Google Scholar
6. Wu, J., PhD thesis, University of the Witwatersrand (1997).Google Scholar
7. Mclachlan, D. S., J. Phys. C18, Sol. Stat. Phys., 1891–97 (1985).Google Scholar
8. Mclachlan, D.S., Blaszkiewicz, and Newnham, R.E., J. Am. Ceram. Soc. 73, 2187–2203 (1990).Google Scholar
9. Maclachlan, D.S., MRS proceedings, v 411, p309–320 (1996).Google Scholar
10. Flux, F., J. Mater. Sci. 28, 285–301(1993).Google Scholar
11. Balberg, I., Phil. Mag. B, vol. 56, no. 6, 991–1003 (1987).Google Scholar
12. Yagil, Y., Deutscher, G. and Bergman, D. J., Int. J. Mod. Phys. B, vol. 7, no. 19, 3353–74 (1993).Google Scholar
13. Dutta, P. and Horn, P. M., Rev. Mod. Phys., vol. 53, no. 3, 497–516 (1981).Google Scholar
14. Rammal, R., Tannous, C., Breton, P., and Tremblay, A.M.S., Phys. Rev. Lett. 54, no. 15, 1718–21(1985).Google Scholar
15. Chen, C. and Chou, Y. C., Phys. Rev. Lett. 54, no. 23, 2529–32 (1985).Google Scholar
16. Wu, J. and Mclachlan, D.S., Phys. Rev. B 56, 1236 (1997).Google Scholar
17. Rammal, R. et al, Phys. Rev. B, vol. 42, no. 6, 3386–94 (1990).Google Scholar