Effect of Cu doping on the structure and phase transition of directly synthesized FePt nanoparticles

In this work, ternary Cu doped FePt nanoparticles were prepared in hexadecylamine at 320 degrees C by choosing FeCl2 as the Fe source. The experimental results showed that without Cu doping the as-prepared FePt nanoparticles possessed fcc structure and gradually exhibited typical fcl diffraction peaks after increasing the Cu doping concentration. TEM images showed that the FePt nanoparticles had larger size and wider size distribution after introducing Cu additive. Magnetic property measurement showed that a coercivity of 4800 Oe was obtained when the composition of the ternary nanoparticles reached Fe35Pt45Cu20, in which the content of Fe+Cu was higher than Pt. The research indicates that Cu doping promotes the phase transition of FePt nanoparticles at temperature as low as 320 degrees C.