Open Access

G. L. Katona, P. V. Makushko, N. Y. Schmidt, O. Lik, T. I. Verbytska, G. Beddies, D. L. Beke, Manfred Albrecht, Iu. N. Makogon

• In this work the diffusion-induced formation of an ordered L10 FePt phase in Fe(15 nm)/Ag(Au)(10 nm)/Pt(15 nm) and Pt(15 nm)/Ag(Au)/Fe(15 nm) trilayers with a Ag(Au) interlayer upon annealing is studied. The films were prepared by magnetron sputtering on SiO2/Si(001) substrates. Isothermal annealing of the samples was carried out in vacuum at 700 °С for different annealing times up to 30 minutes. It was found that the stacking sequence of the trilayer has a strong impact on the direction of the diffusion process. This results in the formation of different chemical composition along the film thickness which is explained by the different formation enthalpies of possible phases. Finally, the hard magnetic L10 FePt phase is formed with grain boundaries filled by Ag(Au) resulting in enhanced coercivity. In addition, depending on the layer stacking sequence, the remaining Ag(Au) can be found either on the top surface or at the substrate interface. In this regard, employing differentIn this work the diffusion-induced formation of an ordered L10 FePt phase in Fe(15 nm)/Ag(Au)(10 nm)/Pt(15 nm) and Pt(15 nm)/Ag(Au)/Fe(15 nm) trilayers with a Ag(Au) interlayer upon annealing is studied. The films were prepared by magnetron sputtering on SiO2/Si(001) substrates. Isothermal annealing of the samples was carried out in vacuum at 700 °С for different annealing times up to 30 minutes. It was found that the stacking sequence of the trilayer has a strong impact on the direction of the diffusion process. This results in the formation of different chemical composition along the film thickness which is explained by the different formation enthalpies of possible phases. Finally, the hard magnetic L10 FePt phase is formed with grain boundaries filled by Ag(Au) resulting in enhanced coercivity. In addition, depending on the layer stacking sequence, the remaining Ag(Au) can be found either on the top surface or at the substrate interface. In this regard, employing different diffusion paths on selected layer stacks is a promising approach of forming gradient nanomaterials with properties that might be useful for practical applications.…