Coverage-dependent magnetization of 3d transition-metal adatoms on Co(001) in the submonolayer regime

摘要

The electronic structure of 3d transition-metal atoms on face-centered cubic Co(001) substrate is determined within ab initio density functional calculations in the gradient corrected approach. Calculations are performed for ordered surface configuration with coverage equal to 0.25, 0.5, 0.75 and 1 ML. For Ni and Fe a ferromagnetic coupling with the Co atoms is always obtained independently of the concentration. Moreover the values of the magnetic moments remain similar. For Mn a ferromagnetic coupling is obtained for low-coverage whereas an in-plane antiferromagnetic coupling is found for a complete Mn overlayer on Co(001). Also, for Sc, Ti, V and Cr a drastic modification of the magnetic map is observed when we go from low-coverage to the monolayer. Cr (Mn) adatoms present anti-ferromagnetic (ferromagnetic) coupling with Co(001) for x = 0.25 whereas an in-plane antiferrimagnetic coupling is obtained for x=1.00.