Electron Beam Tuning of the Magnetic Anisotropy in Co/Cu(110) Films

The 90° in-plane spin reorientation transition caused by residual gas adsorption in the Co/Cu(110) system has been investigated using Mott electron polarimetry. The system displays a 3-D growth mode, forming islands with a preferential axis of elongation along the [1-10] direction. The adsorption of CO at the step edges is found to change the net anisotropy of the system and bring about the change in the relaxed magnetization direction. By carefully limiting the duration of electron beam exposure, it has been shown that this spin rotation can also be observed using Mott polarimetry, where it manifests itself as variations in the secondary electron spin polarization. Extended exposure of the switched film to an electron beam can reverse the easy axis direction, allowing local tuning of the magnetic anisotropy in this system.