Sharif Digital Repository

Due to the strong magnetic anisotropy energy, the L10 FePt nanocrystals are considered as one of promising candidates for magnetic recording media with ultrahigh densities. The surfaces of Si and SiO2 wafers have been covered by FePt nanoparticles (NPs) and heated at 600 °C for 1 h to form the L10 phase. Bonding of NPs with the SiO2 surface in the presence of magnetic field during annealing process controls the L10 FePt NPs size and their uniform surface distribution. In the presence of perpendicular magnetic field to the surface, the size of NPs obtains up to 30 nm with coercivity of 5.8 kOe and in parallel magnetic field, the NPs size reaches to 45 nm with coercivity of 2.9 kOe. These... 

The monosize formation, the ability of self-assembly, and high coercivity after annealing are the properties that lead to the priority of FePt magnetic nanoparticles for the application in recording media. These nanoparticles were synthesized by the superhydride method. The effect of oleic acid and oleylamin ligands on the fabrication of nanocrystals and the stability of the FePt system has been studied. TEM, EDS, XRD, and spectrophotometer analysis show the formation of FePt nanoparticles dispersion in hexane and indicate that oleylamine increases the number of particles in the nucleation stage and decreases the size of the Pt core, whereas the oleic acid controls the shell of the particle...