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The growth morphology and electronic structure of Co(0001) grown on W(110) are studied using scanning tunneling microscopy and scanning tunneling spectroscopy (STS) at T = 6 K. Depending on growth conditions, continuous Co films or Co islands on top of a wetting layer are formed. Within the continuous films, dislocation lines appear and increase in density after annealing. Co islands and films exhibit dI / dV curves with a pronounced peak at −0.3 eV below the Fermi energy. The intensity of this peak is changing in different areas of the surface. Using monolayer high islands with a different shape deposited on the same Co layer we attribute the different intensity to a different stacking of the Co surface. The change in intensity is reproduced by first-principles electronic structure calculations, which reveal that the peak is caused by a d 3z 2 −r 2-like surface resonance of a minority-spin character more strongly coupled to the bulk states in the case of hcp (ABA) stacking than in the case of fcc (ABC) stacking. An increased STS intensity of the surface resonance was also found above dislocation lines located at the Co/W interface. 70 035404-1 FIG. 9. The calculated vacuum DOS of the unfaulted structure (black) and of the faulted structure (gray) of a 12 ML Co film at a distance of 3 Å from the surface layer. Maj, min, and maj + min indicate the majority DOS, the minority DOS, and the sum of both, respectively. All curves are shown on the same scale.

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The magnetic and electronic properties of a Fe monolayer on InAs͑110͒ are calculated with an ab initio method using the density-functional theory. We find that the relaxation of the InAs͑110͒ surface is completely lifted and that the Fe atom is located in the center of the triangle formed of two As atoms and an adjacent In atom. The Fe bonding is largely determined by a molecularlike interaction of As and In orbitals with the Fe d levels. In particular, the density of states at the Fermi level is dominated by a bond between minority Fe d xy , d zy levels and As p x , In sp levels. This leads to a large value of 80% spin polarization on the Fe side and 60% on the InAs side of the interface albeit of different orientation. Into the crystal the spin-polarization exhibits a damped oscillation.

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