Date of this Version
Nano Letters 13:10 (2013)
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 L10−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 L10−FePd−Fe nanocomposite magnets for understanding exchange coupling at the na-noscale. The concept may be extended to other magnetic nanocomposite systems and may help to build superstrong magnets for magnetic applications.