Journal de la science des matériaux et des nanomatériaux

Abstrait

Unexpected Spin-flipping in High Magnetic Nano-Fe3O4

Tun Seng Herng

The search for high resistive soft magnet that coexists of a giant magnetization (>1 T) and high resistivity in a single compound has been intense in recent a year, which is driven by the strong industrial demand for new high-permeability thin films with GHz operating frequencies. One of crucial criterion in this new high resistive soft magnet is the necessity of achieving a higher resistivity than conventional metallic magnets, to limit eddy current screening, while maintaining the high permeability and high saturated magnetization of materials. Among the soft magnetic materials, magnetite (Fe3O4) is particular fascinating owing to its superior magnetic properties (halfmetallic behaviour and high curie temperature of ~860 K) and it has higher resistivity as compared to metallic iron. Moreover, the earlier experimental have demonstrated magnetization enhancement in FePt and Fe3O4 nanocomposite magnets by nanoparticle self-assembly. These intriguing properties of Fe3O4 have stimulated us to study this materials system intensively.