Controllable modification of the anisotropy energy in Laves phase YFe2 by Ar+ ion implantation

Implanted 3.25 keV Ar+ ions have been used to modify the in-plane bulk anisotropy in thin films of epitaxially grown Laves phase YFe2. The magneto optical Kerr effect, vibrating sample magnetometry and computational modeling have been used to show that the dominant source of anisotropy changes from magnetoelastic in as-grown samples to magnetocrystalline in ion implanted samples. This change occurs at a critical fluence of order 1017 Ar+ ions cm-2. The change in source of the anisotropy is attributed to a relaxation of the strain inherent in the epitaxially grown thin-films. Atomic force microscopy shows that the samples' topography remains unchanged after ion implantation. The ability to control the dominant source of magnetic anisotropy without affecting the sample surface could have important consequences in the fabrication of patterned media for high use in density magnetic data storage devices.