Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-26T04:36:07.012Z Has data issue: false hasContentIssue false
  • English
  • Français

Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films

Published online by Cambridge University Press:  26 February 2011

Djamel Kaoumi ,
Arthur T. Motta  and
Robert C. Birtcher
Djamel Kaoumi
Affiliation:
[email protected], Pennsylvania State University, Mechanical and Nuclear Engineering, 18 Reber Bldg, University Park, PA, 16802, United States, 8148832611
Arthur T. Motta
Affiliation:
[email protected], Pennsylvania State University, Mechanical and Nuclear Engineering, United States
Robert C. Birtcher
Affiliation:
[email protected], Argonne National Laboratory, Materials Science Division, United States
Get access

Abstract

In situ observations in a transmission electron microscope (TEM) were used to study ion-beam enhancement of second-phase precipitation in Zr-Fe nanocrystalline thin films. The free-standing films were prepared by co-sputter deposition with an Fe content of 1.2 at%. TEM diffraction analysis showed that only the hcp Zr crystal structure was present in the as-deposited films. No second phases were detected, although Rutherford Backscattering Spectroscopy (RBS) confirmed a Fe content beyond the solubility limit of Fe in Zr (of the order of ppm). This means the thin films were Zr solid solutions supersaturated with Fe. Heat treatment in the absence of irradiation was observed to cause precipitation of the Zr2Fe intermetallic phase, but only above 673 K. The same second-phase precipitation can occur at lower temperatures in the presence of ion irradiation. Samples were irradiated in-situ at the Intermediate Voltage Electron Microscope (IVEM) at Argonne National Laboratory with Kr ions to fluences in excess of 1016 ion/cm2, at temperatures ranging from 50 to 573 K. Second phase precipitation was detected by electron diffraction patterns and by dark field imaging comparing regions exposed to the beam with regions protected from the beam by the TEM support grid. Precipitation of Zr2Fe intermetallic phase was observed at all irradiating temperatures above room temperature. In the bulk, this phase is thermodynamically metastable in the range of temperatures investigated (relative to the orthorhombic Zr3Fe intermetallic phase). The kinetics of the irradiation-enhanced second-phase precipitation was followed by recording the diffraction patterns at regular intervals. The dose to precipitation was found to decrease with increasing irradiation temperature.

Keywords

ion-solid interactionssecond phasestransmission electron microscopy (TEM)
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 908: Symposium OO – Growth, Modification, and Analysis by Ion Beams at the Nanoscale , 2005 , 0908-OO04-04
Copyright
Copyright © Materials Research Society 2006

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

1 Altounian, Z., Volkert, C.A., and Strom-Olsen, J.O., Crystallization characteristics of FeZr metallic glasses from Fe43Zr57 to Fe20Zr80. J. Appl. Phys., 1984 57(6): p. 1777–1782.Google Scholar
2 Cauvin, R. and Martin, G., Radiation Induced Homogeneous Precipitation in Undersaturated Solid Solutions. Journal of Nuclear Materials, 1979 83: p. 67–78,.Google Scholar
3 Bellon, P. and Martin, G., Irradiation-induced formation of metastable phases: A master-equation approach. Physical Review B, 1988 38(4): p. 2570–2582.Google Scholar
4 Martin, G., Phase Stability under Irradiation: Ballistic Effects. Physical Review B, 1984 30(3): p. 1424–1436.Google Scholar
5 Martin, G., Bellon, P., and Soisson, F., Alloys under irradiation. Journal of Nuclear Materials, 1997 251: p. 86–88.Google Scholar
6 Borrelly, R., Merle, P., and Adami, L., Study of the solubility of iron in zirconium by thermoelectric power measurements. Journal of Nuclear Materials, 1989 170: p. 147–156.Google Scholar
7 Allen, C.W. and Ryan, E.A.. In-Situ Ion Beam Research in Argonne's Intermediate Voltage Electron Microscope. in Mat.Res. Soc. Symp. Proc. 1997.Google Scholar
8 Ziegler, J., Biersack, J.P., and Littmark, U., The Stopping and Range of Ions in Matter. 1985, New York: Pergamon Press.Google Scholar
9 Okamoto, H., Fe-Zr (Iron-Zirconium). Journal of Phase Equilibria, 1993 14(5): p. 652–653.Google Scholar
10 Bhanumurthy, K., Kale, G.B., and Khera, S.K., Reaction Diffusion in the Zr-Fe system. Journal of Nuclear Materials, 1991 185: p. 208–213.Google Scholar
11 Motta, A.T., Amorphization of Intermetallic Compounds under Irradiation-a Review. Journal of Nuclear Materials, 1997 244(3): p. 227–250.Google Scholar