Magnetic anisotropy in Fe films deposited on SiO2/Si(001) and Si(001) substrates

The magnetic anisotropy of 10 nm iron films deposited in an ultra high vacuum on the Si(001) surface and on the Si(001) over caped by 1.5 nm layer of SiO2 was investigated. There is in-plane uniaxial magnetic anisotropy caused by oblique sputtering in the Fe films On a SiO2 buffer layer. The easy magnetization axis is always normal to the atomic flux direction but the value of the anisotropy held is different depending on the axial angle among sputtering direction and the substrate crystallographic axes. It is argued that the uniaxial magnetic anisotropy results from elongated surface roughness formation during film deposition. Several easy magnetization axes are found in Fe/Si(001) film without the SiO2 buffer layer. The mutual orientation of the main easy axes and Si crystallographic axes indicates that there is epitaxial growth of Fe/Si(001) film with the following orientation relative to the substrate: Fe[100] parallel to Si[110]. The anisotropy energy of Fe/Si(001) film is estimated by simulation of angle dependence of remnant magnetization air as the sum of the m(r) angle plot from uniaxial anisotropy (induced by oblique deposition) and the polar plot from biaxial magnetocrystalline anisotropy. (C) 2013 Elsevier B.V. All rights reserved.