Strong uniaxial magnetic anisotropy in conformally grown co films on ion-beam patterned ge surfaces

We present a systematic investigation on uniaxial magnetic anisotropy in Co thin films induced by high aspect ratio nano-patterned, anisotropic substrates. Self-organized, long grating-like nanostructures are fabricated on Ge surfaces using Au-ion implantation at room temperature. Subsequently deposition of Co films are carried out on the same at two different angles. Magneto-optical Kerr effect measurements show a strong uniaxial magnetic anisotropy in Co films as a function of ion fluence (used during the fabrication of Ge patterns) along and perpendicular to the direction of the patterns (long grating-like nanostructures). With increasing ion fluence topographical defects are annihilated on Ge surfaces that leads to an increase in magnetic anisotropy. (author)