Direct Synthesis of L10-FePt Nanoparticles with High Coercivity via Pb Addition for Applications in Permanent Magnets and Catalysts

We report a promising strategy to directly synthesize L1(0)-FePt nanoparticles for applications in permanent magnets and catalysts. The element Pb with lower melting point, smaller surface energy, and a bigger atomic radius can improve migration of Fe and Pt atoms and promote orderly diffusion in the L1(0)-FePt nanoparticles by generating vacancies and lattice distortion. The ordering degree and magnetic properties of the nanoparticles can be tuned by changing the molar ratios of Pb/Pt and removing Pb from the nanoparticles. The ultrahigh ordering degree and a coercivity of up to 20.95 kOe were achieved by using a suitable Pb/Pt ratio after removing Pb.