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Microstructural and chemical effects in Al2O3 implanted with iron at 77 K and annealed in oxidizing or reducing atmospheres

Published online by Cambridge University Press:  31 January 2011

C.J. McHargue
Affiliation:
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6118
P.S. Sklad
Affiliation:
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6118
C.W. White
Affiliation:
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6118
J.C. McCallum
Affiliation:
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6118
A. Perez
Affiliation:
Département de Physique des Matériaux, Université Claude Bernard Lyon 1, Villeurbanne Cedex, France
G. Marest
Affiliation:
Institut de Physique Nucléaire de Lyon, IN2P3-CNRS, Université Claude Bernard Lyon 1, Villeurbanne Cedex, France
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Abstract

Implantation of Fe (160 keV) into α–Al2O3 at 77 K produces an amorphous surface layer for fluences in the range of 1016 to 1017 Fe/cm2. Measurements of short-range order were made by extended energy loss fine structure analysis (EXELFS). The structure of amorphous Al2O3 produced by implantation of iron at 77 K exhibits short-range order that differs from that produced by stoichiometric (Al + O) implants. This difference is manifested by changes in the Al–O near-neighbor bond length. The local environments of implanted iron were determined from conversion electron Mössbauer spectroscopy (CEMS). The iron resides in several different local environments consistent with the electronic states of Fe2+, Fe4+, and Fe0. The relative amount of each environment depends upon the concentration (fluence) of the implanted iron ions. Regrowth of the amorphous zone during annealing occurs in the sequence amorphous → γ–Al2O3 ↠ α–Al2O3. The kinetics of regrowth and phase separation vary with implanted fluence and with annealing atmosphere. The higher the concentration of implanted iron, the slower the formation of iron-aluminum oxide precipitate phases in oxidizing atmospheres and α–Fe precipitates in reducing atmospheres.

Type
Articles
Copyright
Copyright © Materials Research Society 1991

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References

1.McHargue, C. J., Farlow, G. C., White, C. W., Appleton, B. R., Angelini, P., and Naramoto, H., Nucl. Instrum. Methods in Phys. Res. B10/11, 569 (1985).CrossRefGoogle Scholar
2.McHargue, C. J., Sklad, P. S., White, C. W., Farlow, G. C., Perez, A., and Marest, G., J. Mater. Res. 6, 2145 (1991).CrossRefGoogle Scholar
3.Sklad, P. S., Angelini, P., and Sevely, J., in Proc. 46th Annual Meeting of the Electron Microscopy Society of America, edited by Bailey, G. W. (San Francisco Press, San Francisco, CA, 1988), p. 468.Google Scholar
4.Sawicka, B. D. and Sawicki, J. A., in Topics in Current Physics, edited by Gonser, U. (Springer, Berlin, 1981), pp. 136166.Google Scholar
5.Sklad, P. S., McCallum, J. C., Pennycook, S. J., McHargue, C. J., White, C. W., and Perez, A., in Characterization of the Structure and Chemistry of Defects in Materials, edited by Larson, B. C., Riihle, M., and Seidman, D. N. (Mater. Res. Soc. Symp. Proc. 138, Pittsburgh, PA, 1989), p. 119.Google Scholar
6.Rossiter, M. J., J. Phys. Chem. Solids 26, 775 (1965).CrossRefGoogle Scholar
7.Greenwood, N. N. and Gibb, T. C., Mössbauer Spectroscopy (Chapman and Hill Ltd., London, 1971), p. 249.CrossRefGoogle Scholar
8.Fournier, L., Potin, Y., Grenien, J. C., Demazeau, G., and Pouchard, M., Solid State Commun. 62, 239 (1987)Google Scholar
9.Demazeau, G., Li-Ming, Z., Fournier, L., Pouchard, M., and Hagenmuller, P., J. Solid State Chem. 72, 31 (1988).CrossRefGoogle Scholar
10.Demazeau, G., Buffat, B., Pouchard, M., and Hagenmuller, P., J. Solid State Chem. 52, 389 (1984).CrossRefGoogle Scholar
11.White, C. W., Boatner, L. A., Sklad, P. S., McHargue, C. J., Rankin, J., Farlow, G. C., and Aziz, M. J., Nucl. Instrum. Methods Phys. Res. B32, 11 (1988).CrossRefGoogle Scholar