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Electrocatalysis of Pt-Fe alloys produced by ion beam mixing

Published online by Cambridge University Press:  31 January 2011

M. G. Fernandes ,
D. A. Thompson ,
W. W. Smeltzer  and
J. A. Davies
M. G. Fernandes
Affiliation:
Department of Engineering Physics and Institute for Materials Research, McMaster University, Hamilton, Ontario, Canada L8S 4M1
D. A. Thompson
Affiliation:
Department of Engineering Physics and Institute for Materials Research, McMaster University, Hamilton, Ontario, Canada L8S 4M1
W. W. Smeltzer
Affiliation:
Department of Engineering Physics and Institute for Materials Research, McMaster University, Hamilton, Ontario, Canada L8S 4M1
J. A. Davies
Affiliation:
Department of Engineering Physics and Institute for Materials Research, McMaster University, Hamilton, Ontario, Canada L8S 4M1
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Abstract

Ion beam mixing using 120 keV Fe+ ions at doses varying from 3.0 to 20 ⊠ 1015 cm2 was carried out on Pt–Fe bilayer samples over a temperature range from 298 to 523 K to produce alloys of various compositions. The mixing was characterized using Rutherford backscattering with 2 MeV 4He+ ions and transmission electron microscopy. Ion beam mixing and thermal anneals led to grain growth of the polycrystalline films and to formation of Pt3Fe as an alloy phase. At T ≤ 373 K, mixing was athermal and took place by ballistic collisional processes. At T ≥ 473 K, iron migrated rapidly into platinum; the observed activation energy of 0.3 eV suggested that diffusion was of the short-circuit type controlled by lattice vacancy and grain boundary transport. The surface Pt concentration in the mixed films remained high at ∼90 at. %. This resulted in a reduction of ∼25% in the cathodic overpotential compared to pure Fe electrodes for H2 evolution in 30 wt. % KOH solution. An ion beam mixed Pt–Fe surface layer was more stable than Fe coated with evaporated Pt; this is attributed to improved Pt–Fe adhesion as a result of the ion beam mixing process.

Type
Articles
Information
Journal of Materials Research , Volume 5 , Issue 1 , January 1990 , pp. 98 - 108
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1 Kasten, H. and Wolf, G. K., Elec. Acta 25, 1581 (1980).CrossRefGoogle Scholar
2 Chan, W. K., Clayton, C. R., Allas, R. G., Gossett, C. R., and Hirvonen, J. K., Nucl. Instrum. Methods 209/210, 857 (1983).CrossRefGoogle Scholar
3 Fedrizzi, L., Guzman, L., Molinari, A., and Girardi, S., Nucl. Instrum. Methods B7/8, 711 (1985).Google Scholar
4 Giner, J., J. Electrochem. Soc. 111, 376 (1964).CrossRefGoogle Scholar
5 Averback, R. S., Nucl. Instrum. Methods B15, 675 (1986).CrossRefGoogle Scholar
6 Poker, D. B. and Appleton, B. R., Mater. Res. Soc. Symp. Proc. 45, 171 (1985).Google Scholar
7 Chu, W. K., Mayer, J. W., and Nicolet, M-A., Backscattering Spectrometry (Academic Press, Inc., 1978).CrossRefGoogle Scholar
8 Koshkin, V. K., Rysov, J. A., Shkarban, I. I., and Gourmin, B. M., Proc. 9th Int. Conf. Phenomena of Ionized Gases, Bucharest (1969), p. 92.Google Scholar
9 Sletten, G. and Knudsen, P., Nucl. Instrum. Methods 102, 459 (1972).Google Scholar
10 Ziegler, J. F., Biersack, J. P., and Littmark, U., TRIM88, distributed by IBM (1988).Google Scholar
11 Shewmon, P. G., Diffusion in Solids (McGraw-Hill, New York, 1963).Google Scholar
12 Takamura, S., Radiat. Eff. Lett. 43, 69 (1979).CrossRefGoogle Scholar
13 Frank, W. and Seeger, A., Radiat. Eff. 31(1967).Google Scholar
14 Dienes, G. J. and Damask, A. C., J. Appl. Phys. 29, 1713 (1958).CrossRefGoogle Scholar
15 Akano, U. G., Thompson, D. A., Smeltzer, W. W., and Davies, J. A., J. Mater. Res. 3, 1063 (1988).Google Scholar
16 Liou, K. Y. and Wilkes, P. J., J. Nucl. Mater. 87, 317 (1979).Google Scholar
17 Silverman, D. C., Corrosion 38, 453 (1982).Google Scholar
18 Pourbaix, M. J. N., Atlas of Electrochemical Equilibria in Aqueous Solutions, NACE (1974).Google Scholar
19 Geronov, L M., Tomov, T., and Georgiev, S., J. Appl. Electrochem. 5, 351 (1975).CrossRefGoogle Scholar