Structural characterization of epitaxial Cr(x)Mo(1-x) alloy thin films.

Abstract

To develop a model system containing regularly spaced misfit dislocations for studies of the radiation resistance of nanoscale defects, epitaxial thin films of Cr, Mo, and Cr(x)Mo(1-x) alloys were deposited on MgO(001) by molecular beam epitaxy. Film compositions were chosen to vary the lattice mismatch with MgO. The film structure was investigated by x-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and scanning transmission electron microscopy (STEM). Epitaxial films with reasonably high crystalline quality and abrupt interfaces were achieved at a relatively low deposition temperature, as confirmed by STEM. However, it was found by XRD and RBS in the channeling geometry that increasing the Mo content of the CrMo alloy films degraded the crystalline quality, despite the improved lattice match with MgO. XRD rocking curve data indicated that regions of different crystalline order may be present within the films with higher Mo content. This is tentatively ascribed to spinodal decomposition into Cr-rich and Mo-rich regions, as predicted by the Cr(x)Mo(1-x) phase diagram.

• Authors: T C Kaspar, M E Bowden, T Varga, C M Wang, V Shutthanandan, A G Joly, B D Wirth, R J Kurtz
• Journal: Journal of physics. Condensed matter : an Institute of Physics journal (J Phys Condens Matter) Vol. 24 Issue 9 Pg. 095001 (Mar 07 2012) ISSN: 1361-648X [Electronic] England
• PMID: 22274988 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Alloys
• Chromium
• Molybdenum

Topics

• Alloys (chemistry)
• Chromium (chemistry)
• Materials Testing
• Microscopy, Electron, Scanning
• Molybdenum (chemistry)
• Surface Properties
• X-Ray Diffraction