FABRICATION OF EXCHANGE COUPLED HARD/SOFT NANOCOMPOSITE MAGNET AND THEIR CHARACTERIZATION.

Monodispersed α-Fe nanoparticles were synthesized under an argon atmosphere via thermal decomposition of Fe2+-oleate2. Nd–Fe–B ultrafine amorphous alloy particles were prepared by reaction of metal ions with borohydride in aqueous solution. Exchange coupled Nd2Fe14B/α-Fe nanocomposite magnets have been prepared by self-assembly using surfactant. The crystal structure of the synthesized nanoparticles was identified by using X-ray powder diffraction (XRD). The size and shape of nanoparticles were obtained by TEM. Thermogravimetry using a microbalance with magnetic field gradient positioned below the sample was used for the measurement of a thermomagnetic analysis (TMA) curve showing the downward magnetic force versus temperature. [ABSTRACT FROM AUTHOR]