Preparation of FePt Nanoparticles with Flower-Like Assembly

FePt nanoparticles with flower-like assembly were synthesized at room temperature by a simple wet chemical reduction process using NaBH4 as the reducing reagent and PEG as the surfactant. XRD and TEM characterizations show that the as-synthesized FePt particles are possessed of chemically disordered face-centered cubic (fcc) structure. The shapes present the fusiform and the spherical with the mean sizes of 19.2 and 4.9 nm, respectively. These fusiform "petals" and spherical "stamens" are found to be assembled into flower-like structures. We suggest that the formation of flower-like assemble of FePt nanoparticles is result from the surfactant assemblage. VSM indicates that the as-synthesized samples show paramagnetic property at room temperature with the saturation magnetization M-s 10.9 (A.m(2))/kg. when PVP is used as surfactant, M-s is about 0.6 (A.m(2))/kg. comparing the nanoparticles synthesized and the same condition, M-s increases by 18 times when PEG is used as surfactant.