Preparation and properties of ferromagnetic FePt dispersion

FePt nanoparticles were prepared via the coreduction of platinum and iron acetyl acetonate precursors in tetraethylene glycol at various temperatures. The X-ray diffractogram of the as-synthesized FePt nanoparticles at temperatures above 573 K exhibited (0 0 1) and (1 1 0) superlattice reflections. TEM-EDX studies revealed that the average particle diameter was 5 nm with nearly equiatomic composition. The saturation magnetization and coercivity at room temperature (RT) were found to be 50 emu/g and 2.1 kOe, respectively. The high anisotropy field of about 32 kOe and magnetic ordering at RT revealed the presence of the highly anisotropic L10 phase. These particles were partially dispersed in an organic solvent using oleyl amine as surfactant. The dispersed FePt nanoparticles will be useful in future technological applications.