Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-02T23:45:29.267Z Has data issue: false hasContentIssue false

Temperature Dependence of Kr Precipitation in Ni

Published online by Cambridge University Press:  26 February 2011

R. C. Birtcher
Affiliation:
Materials Science Division, 9700 S. Cass Ave., Argonne National Laboratory, Argonne, IL 60439
A. S. Liu
Affiliation:
Materials Science Division, 9700 S. Cass Ave., Argonne National Laboratory, Argonne, IL 60439
Get access

Abstract

The precipitation of Kr injected into Ni at temperatures between 25 and 560 C has been studied with transmission electron microscopy. The Kr precipitates in cavities which increase in size with Kr fluence. Electron diffraction and dark-field imaging demonstrate that small Kr precipitates are solid, fcc crystals aligned with each other and the Ni lattice. The Kr is held in the solid state by the pressure generated by the cavity walls, and this pressure decreases with increasing cavity size. The mismatch between the Kr and Ni lattices is as large as 55%. The average Kr lattice parameter, determined from electron diffraction at room temperature, increases with increasing Kr fluence from 0.515 nm to an asymptotic value of about 0.545 nm for implantations at temperatures of 300 C or less. This increase towards an asymptotic limit is due to expansion of the Kr lattices as precipitates grow, until the decrease in cavity pressures allows melting of solid Kr in large cavities. Diffuse electron scattering was observed from liquid Kr in large precipitates for fluences greater than 5·1020Kr+m−2. Implantations at temperatures of 400 C or higher result in a bi-modal size distribution containing small solid precipitates and an additional population of larger, faceted precipitates, a larger average Kr lattice parameter for a given Kr fluence, and a higher asymptotic lattice parameter of 0.550 nm. Solid Kr seems to inhibit motion of small precipitates, and Kr melting is a precursor to faceting and growth by coalescence.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

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. Felde, A. vom, Fink, J., Müller-Heinzerling, Th., Pflürger, J., Scheerer, B. and Linker, G., Phys. Rev. Lett. 53 ,922 (1984).CrossRefGoogle Scholar
2. Evans, J. H. and Mazey, D. J., J. Phys. F: Met. Phys. 15, L1 (1985).Google Scholar
3. Birtcher, R. C. and Jäger, W., Ultramicroscopy, 22, 267 (1987).Google Scholar
4. Birtcher, R. C. and Liu, A. S., in Beam-Solid Interactions and Transient Processes, edited by Thompson, M. O., Picraux, S.T. and Williams, J.S. (Mater. Res. Soc. Proc. 74, Boston, MA 1986) pp. 345350.Google Scholar
5. Biersack, J. and Haggmark, L. G., Nucl. Instr. and Meth. 174, 257 (1980).CrossRefGoogle Scholar
6. Andersen, H. H. and Bay, H. L., in Sputtering by Particle Bombardment 1, Behrisch, R. ed. Topic Appl. Phys., vol.47 (Springer, Berlin 1981), page 145.Google Scholar
7. Liu, A. S. and Birtcher, R. C., to be published.Google Scholar
8. Lahr, P. H. and Eversole, W. G., J. Chem. Eng. data 7, 42 1962.Google Scholar
9. Pearson, W. B., A Handbook of Lattice Spacings and Structures of Metals and Alloys, Pergamon, 1958.Google Scholar
10. Rest, J. and Birtcher, R. C., 14 Int. Symp. Effects Radiat. on Mater. June 27–29, 1988, Andover, MA, USA.Google Scholar