L1₀ FePt-C nanogranular perpendicular anisotropy films with narrow size distribution

We report the study of L1₀ FePt-C nanogranular perpendicular anisotropy films fabricated on oxidized Si substrates with a (100) textured MgO Intermediate layer. The addition of a small amount of C (<12%) to a FePt (4nm) film results in the formation of interconnected FePt particles, while a higher C addition leads to the formation of well-isolated L1₀ FePt nanoparticles with a c-axis texture. The FePt particle size can be reduced to 5.5 nm with a size distribution of 2.3 nm in variance by adjusting FePt thickness. Perpendicular coercivity is controllable between 8 and 15 kOe with high squareness. These results demonstrate that the FePt-C system can accomplish a nanogranular structure suitable for ultrahigh density perpendicular recording media.