@article { ISI:000320948700003, title = {Spin relaxation and the Elliott-Yafet parameter in W(001) ultrathin films: Surface states, anisotropy, and oscillation effects}, journal = {PHYSICAL REVIEW B}, volume = {87}, number = {22}, year = {2013}, month = {JUN 24}, pages = {224420}, abstract = {Using first-principles methods based on density-functional theory, we investigate the spin relaxation in W(001) ultrathin films. Within the framework of the Elliott-Yafet theory, we calculate the spin mixing of the Bloch states and we explicitly consider spin-flip scattering off self-adatoms. At small film thicknesses, we find an oscillatory behavior of the spin-mixing parameter and relaxation rate as a function of the film thickness, which we trace back to surface-state properties. We also analyze the Rashba effect experienced by the surface states and discuss its influence on the spin relaxation. Finally, we calculate the anisotropy of the spin-relaxation rate with respect to the polarization direction of the excited spin population relative to the crystallographic axes of the film. We find that the spin-relaxation rate can increase by as much as 27\% when the spin polarization is directed out of plane, compared to the case when it is in plane. Our calculations are based on the multiple-scattering formalism of the Korringa-Kohn-Rostoker Green-function method.}, issn = {2469-9950}, doi = {10.1103/PhysRevB.87.224420}, author = {Long, Nguyen H. and Mavropoulos, Phivos and Zimmermann, Bernd and Heers, Swantje and Bauer, David S. G. and Bl{\"u}gel, Stefan and Mokrousov, Yuriy} }