Ab initio investigations of magnetic properties of ultrathin transition ...

6.3 Co atomic chain on Rh(664): 113
E θ,φ −E 0,0 [meV/Co]
Co
m [μΒ ] l
0.5
0.0
−0.5
−1.0
−1.5
−2.0
0.16
0.14
0.12
0.10
75°
Co/Rh(664)
Co
(θ,0)
71°
0.08
−90 −60 −30 0 30 60 90
θ(degree)
Co/Pt(664)
Co
(θ,0)
71°
−90 −60 −30 0 30 60 90
θ(degree)
Figure 6.7: Comparison between the results of relaxed Co decorated Rh (left) and Pt
(right) step edges.
Co might lose its FM, as for Fe, if we tune the substrate from the late through the early
transition metals hexagonal substrates. We calculated the magnetocrystalline anisotropy
of Co and Fe monolayer on 4d-TMs hexagonal substrates. We found that Fe MCA is not
strongly affected by adding the substrate as Co. This lead us to chose Co, as a case of
study, to analyze the MCA of Co atomic chain on microfaceted Rh〈111〉. We compared our
results to previous study of Co chain on Pt〈111〉, and found that relaxations play a crucial
role to determine a consistent magnetization easy axis with the experimental results, since
strong relaxations lead to strong reduction of the theoretical Co orbital moments.