Electronic structure and magnetic behavior of ultra-thin Fe films grown on W(110) with a Co buffer layer

We report on the growth of a Fe/Co bilayer on W(110) and its electronic and magnetic structure characterization by means of low energy electron diffraction and spin-resolved photoemission spectroscopies. The Co bottom layer, investigated in the thickness range from 2 to 10 monolayers (ML), relaxes immediately to its bulk hcp structure and is therefore used to provide an hexagonal top surface for the growth of metastable Fe films. Notwithstanding the presence of the Co layer, and similar to our previous findings concerning the growth of Fe on a Ni layer [Phys Rev B 94 195155], we report the formation of bcc nuclei, indicative of lattice relaxation, even for a Fe thicknesses as low as 2 ML. For all the Fe/Co thickness combinations and at magnetic remanence, we were able to measure a not nil in-plane spectral spin polarization.