In-plane uniaxial magnetic anisotropy of thin Fe layers on Si(111) induced upon grazing deposition of a Si capping layer

We demonstrate that an in-plane uniaxial magnetic anisotropy can be induced in Fe films grown on Si(111) by means of an appropriate Si capping layer. It is shown that grazing-incidence Si deposition reduces the three-fold symmetry of the body-centered-cubic (BCC) Fe(111) surface to two-fold, thus generating a surface-type uniaxial in-plane magnetic anisotropy contribution. The relevant magnetic easy axis direction depends in a critical way on the azimuth of the Si evaporation flux with respect to the Fe crystal surface directions. A simple qualitative model based on the change of the Fe surface by inhomogeneous chemical reaction with Si is proposed to interpret the magnetic anisotropy evolution. (c) 2004 Elsevier B.V. All rights reserved.