title: One-pot synthesis of urchin-like FePd-Fe3O4 and their conversion into exchange-coupled L1(0)-FePd-Fe nanocomposite magnets.
abstract: We report a one-pot synthesis of urchin-like FePd-Fe3O4 nanocomposites, spherical clusters of FePd nanoparticles (NPs) with spikes of Fe3O4 nanorods (NRs), via controlled thermal decomposition of Fe(CO)5 and reduction of Pd(acac)2. The FePd NPs with sizes between 6 and 9 nm self-aggregate into 60 nm superparticles (SPs), and Fe3O4 NRs grow on the surface of these SPs. Reductive annealing at 500 °C converts the FePd-Fe3O4 into exchange-coupled nanocomposites L1(0)-FePd-Fe with their Hc tunable from 0.8 to 2.6 kOe and Ms controlled from 90 to 190 emu/g. The work provides a general approach to L1(0)-FePd-Fe nanocomposite magnets for understanding exchange coupling at the nanoscale. The concept may be extended to other magnetic nanocomposite systems and may help to build superstrong magnets for magnetic applications.
authors.affiliation: Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Yu
authors.forename: Kewei
authors.initials: K
authors.lastname: Sun
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: X-Z
authors.initials: XZ
authors.lastname: Li
authors.forename: M J
authors.initials: MJ
authors.lastname: Kramer
authors.forename: D J
authors.initials: DJ
authors.lastname: Sellmyer
authors.forename: J E
authors.initials: JE
authors.lastname: Shield
authors.forename: Shouheng
authors.initials: S
authors.lastname: Sun
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D059346:Magnets / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D043942:Nanotubes / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties
chemical_list: D005290:Ferric Compounds