Abstract
A thin Ni buffer layer between a W(110) substrate and a Co three-monolayer (ML) film was found to improve the crystallinity of the Co film and enhance its magnetic properties. The use of spin-polarized single- and two-electron spectroscopies allowed the identification of energy- and momentum-resolved spin-related modifications of the electronic structure of 3-ML cobalt film due to an Ni buffer layer on W(110) substrate. The presence of a thin Ni layer (1 to 4 MLs) increased the spin asymmetry of the Co density of states in the center of the Brillouin zone just below the Fermi level. Analysis of the spin asymmetry in the (,2) spectrum of Co film showed the spin-orbit component of asymmetry was readily observable even with 2 and 3 MLs of Ni buffer layers. The shape and magnitude of the asymmetry are similar to those observed in a 3-ML Co film on W(110) without an Ni buffer. This rules out the earlier suggestion that the spin-orbit interaction in the Co film is induced by W(110) substrate via the proximity effect.
1 More- Received 4 June 2011
DOI:https://doi.org/10.1103/PhysRevB.84.184433
©2011 American Physical Society