Surface morphology and magnetic anisotropy of obliquely deposited Co/Si(111) films

Abstract

We report an investigation on magnetic anisotropy of Co/Si͑111͒ films deposited at oblique incidence. An in-plane uniaxial magnetic anisotropy ͑UMA͒ with the easy axis perpendicular to the incident flux plane was observed to superimpose on sixfold magnetocrystalline anisotropy of Co films. We built a total energy model to investigate the magnetization reversal mechanism around hard axis. The simulated value of UMA is K u = 1.7ϫ 10 5 erg/ cm 3 , which is consistent with K shape = 1.1ϫ 10 5 erg/ cm 3 calculated from scanning tunneling microscope image. This good agreement suggests the in-plane UMA is mainly originated from the shape of the oblique deposited Co stripes.

Tuning non-Gilbert-type damping in FeGa films on MgO(001) via oblique deposition

“…This indicates negligible out-of-plane magnetic anisotropy in the thick FeGa films. As shown in figure 2(b), it is observed that the UMA (K u =H u M s /2) exhibits a general increasing trend with oblique angle, which coincides with the fact the shadowing effect is stronger at larger angles of incidence [16][17][18][19]. Interestingly the oblique deposition also affects the cubic anisotropy K 4 (K 4 =H 4 M s /2).…”

“…The obtained maxima of twofold TMS exhibits an increasing trend with the oblique angle (shown in figure 4(c)). According to previous works on the shadowing effect [16][17][18][19], the larger deposition angle makes the shadowing effect stronger, and the dipolar fields within stripelike defects increase just like the UMA. This can clearly explain that the intensity of twofold TMS follows exactly the same trend with the deposition angle as the UMA.…”

“…Here, we report an approach to engineer the damping factor of Fe 81 Ga 19 (FeGa) films by oblique deposition. The FeGa alloy exhibits large magnetostriction and narrow microwave resonance linewidth [15], which could assure it as a promising material for spintronic devices.…”

“…For the geometry of off-normal deposition, it has been demonstrated to provoke shadow effects and create a periodic stripe defect matrix. This can introduce a strong uniaxial magnetization anisotropy (UMA) perpendicular to the projection of the atom flux [16][17][18][19]. Even though some reports have shown oblique deposition provokes a twofold TMS channel [20][21][22], the oblique angle dependence of the intrinsic Gilbert damping and the TMS still remain in doubt.…”

Tuning magnetic anisotropies of Fe films on Si(111) substrate via direction variation of heating current

“…The obstacle resulted from the interdiffusion between the magnetic metals and Si substrates can be overcome via inserting a buffer layer of copper or iron silicides1718. In our previous work19202122, quasi 1D magnetic nanodot assemblies were fabricated on vicinal Si(111) surface with relatively large miscut angles (~4°). Unfortunately, the terrace width of these stepped substrates cannot be tuned easily once the miscut angle is fixed, which causes difficulty in investigating the effect of terrace width on magnetic properties by using identical substrates.…”