Theoretical study of electron-phonon interaction in {beta}-phase NiTi and Ni-Al alloys
The electronic band structure of {beta}-phase NiTi and NiAl was calculated using a first-principles LCAO method, and then fitted by the nonorthogonal empirical tight binding method for the evaluation of electron-phonon (e-ph) matrix elements. Contribution of the e-ph interaction to phonon dynamical matrix was calculated by the method of Varma and Weber. It is found that an accurate calculation of e-ph interaction can explain the behavior of phonon anomalies in {beta}-phase NiTi and Ni-Al alloys. Fermi surface nesting and the symmetric properties of the e-ph interaction matrix elements are attributed as the source of the phonon anomalies and/or the soft phonon in these alloys. The temperature dependence of the phonon anomalies can be explained as a smearing effect of the Fermi surface.
- Research Organization:
- Ames Lab., IA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 10113859
- Report Number(s):
- IS-T-1568; ON: DE93004733
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 17 Sep 1992
- Country of Publication:
- United States
- Language:
- English
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