One-Pot Synthesis of Urchin-like FePd−Fe₃O₄ and Their Conversion into Exchange-Coupled L1₀−FePd−Fe Nanocomposite Magnets

Authors

Yongsheng Yu, Brown University
Kewei Sun, Iowa State University
Yuan Tian, University of Nebraska-Lincoln
Xingzhong Li, University of Nebraska-LincolnFollow
Matthew J. Kramer, Ames Laboratory, USDOEFollow
David J. Sellmyer, University of Nebraska-LincolnFollow
Jeffrey E. Shield, University of Nebraska - LincolnFollow
Shouheng Sun, Brown UniversityFollow

Document Type

Article

Date of this Version

2013

Citation

Nano Letters 13:10 (2013)

Comments

The authors declare no competing financial interest

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 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.