Ultrahigh-density (001)-oriented FePt nanoparticles by atomic-scale-multilayer deposition.

Highly ordered (001)-oriented FePt nanoparticles (NPs) with controllable sizes and well-aligned easy axis were obtained by tuning the total layer number n of atomic-scale [Fe/Pt/SiO₂]_n multilayers deposited on SiO₂∥Si substrates. After annealing at 700 °C, the ordered FePt NPs with a small particle size of 5.5 nm (an extremely high areal density of 1.2×10¹³dots/in.²), a large out-of-plane coercivity of 28.5 kOe, and a narrow size distribution of 13% were attained. All NPs were embedded in the SiO₂ substrates, resulting in a flat top surface. Finally, a full-stack film structure of perpendicular recording media composed of FePt NPs (recording layer), SiO₂ (nonmagnetic intermediate layer) and CoZrTa (soft underlayer) was demonstrated. [ABSTRACT FROM AUTHOR]