Theoretical investigations of phonon anomalies in fcc La and W(001)
Studies of the electron-phonon interaction were carried out for fcc La by the efficient tight-binding method. This scheme was then extended and generalized to surface studies. Application of this extended scheme to the W(001) surface provided detailed information about the driving mechanism for surface reconstruction. Together with the further studies on the Mo(001) surface, the investigation showed very promising potential applications of this scheme to various surface phonon and surface phase-transition studies. For the fcc La, first-principles pseudopotential band-structure calculations were performed and revealed a small but sharp nesting feature of the Fermi surface. The calculations for W(001) p (1x1) surface phonons successfully demonstrated the electronic origin of the c(2x2) surface reconstruction. The reason for the stable M/sub 1/ and soft M/sub 5/ surface-phonon modes was found to be the dramatic differences in their electron-phonon coupling matrix elements. The subtle interplay between the Fermi surface nesting and real-space d-orbital interaction was found to cause the surface reconstruction. Subsequent studies on the Mo(001) surface further established the relationship between these competing effects and surface reconstruction geometries.
- Research Organization:
- Iowa State Univ. of Science and Technology, Ames (USA)
- OSTI ID:
- 6095361
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electronic effects in the Mo(001) surface reconstruction: Two-dimensional Fermi surfaces and nonadiabaticity
Anomalous lattice dynamics of fcc lanthanum