Magnetic properties and structure of Gd-implanted L10 FePt thin films

In this study, we have investigated the effect of Gd implantation on composition, chemical order, and magnetic properties of 20 nm thick L1 ₀ ordered FePt thin films. We show that upon Gd implantation at 30 keV even a small amount of 1 at. % is sufficient to destroy the L1 ₀ order, resulting in a soft magnetic A1 FePt alloy, with the exception of a thin L1 ₀ ordered layer located at the film/substrate interface. Additionally, a strong resputter effect is observed which results in a large decrease in film thickness as well as to a reduction in Fe content in the FePt alloy. Post-annealing of samples in Ar atmosphere did not result in a restoration of the L1 ₀ order, but leads to a transformation to pure Pt and Fe ₂O ₃, facilitated by the presence of a high density of vacancies induced by the implantation process.