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.