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Mechanisms for the Variation of Electrical Resistivity of Palladium Films in Hydridation-dehydridation Processes

Published online by Cambridge University Press:  01 February 2011

Yu Ming Tang
Affiliation:
[email protected], The Hong Kong Polytechnic University, Department of Applied Physics and Materials Research Center, Hung Hom, Kowloon, Hong Kong, N/A, China, People's Republic of
Yiu Bun Chan
Affiliation:
[email protected], The Hong Kong Polytechnic University, Department of Applied Physics and Materials Research Center, Hung Hom, Kowloon, Hong Kong, N/A, China, People's Republic of
Chung Wo Ong
Affiliation:
[email protected], The Hong Kong Polytechnic University, Department of Applied Physics and Materials Research Center, Hung Hom, Kowloon, Hong Kong, N/A, China, People's Republic of
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Abstract

Hydridation of palladium (Pd) is accompanied by a substantial volume expansion. The electrical resistivity (ρ) would rise because the volume fraction of the hydride phase increases. However, if the material structure is porous/defective, hydridation induced volume expansion may lead to the closing of some pores/defects to result in a drop of ρ. We verified that a magnetron sputtered Pd film deposited at a higher argon ambient pressure (ϕ) was more defective, such that the contribution from the latter mechanism was stronger with increasing ϕ, and reached a maximum level for a film deposited at a ϕ of 6 mTorr. However, the film structure was weaker and unstable during the switching cycles, such that the magnitude of the change of ρ was found to increase successively with increasing number of switching cycles. The performances of ρ during initial soaking in H2 and subsequent hydridation and dehydridation switching cycles were different. The observed results are presented and discussed in this paper.

Type
Research Article
Copyright
Copyright © Materials Research Society 2008

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References

1. Lewis, F.A., Palladium Hydrogen System, Academic Press, London, 1967, p.3.Google Scholar
2. Huot, J., Nanoclusters and Nanocrystals, edited by Nalwa, H.S., California, American Scientific Publisher, 2003, p.53.Google Scholar
3. Owen, E.A. and Jones, J.I., Proc. Phys. Soc. 49, A587 (1937).Google Scholar
4. Barton, J.C., Woodward, I. and Lewis, F.A., Trans. Faraday Soc. 59, 1201 (1963).10.1039/tf9635901201Google Scholar
5. Sakamoto, Y. and Takashima, I., J. Phys.: Condens. Matter 8, 10511 (1996).Google Scholar
6. Christofides, C. and Mandelis, A., J. Appl. Phys. 68, R1 (1990).Google Scholar
7. Kumar, M.K., M.Rao, S.R. and Ramaprabhu, S., J. Phys. D: Appl. Phys. 39, 2791 (2006).Google Scholar
8. Favier, F., Walter, E. C., Zach, M. P., Benter, T. and Penner, R. M., Science 293, 2227 (2001).Google Scholar
9. Xu, T., Zach, M. P., Xiao, Z. L., Rosenmann, D., Welp, U., Kwok, W.K. and Crabtree, G.W., Applied Physics Letters 86, 203104 (2005).Google Scholar
10. Luongo, K., Sine, A. and Bhansali, S., Sens. Actuators B: Chem., 111–112, 125 (2005).Google Scholar