RESUMO
Soft phase magnetic Fe-B nanoparticles were prepared by coprecipitation and the hard phase magnetic Nd-Fe-B nanoparticles were obtained from mechanical ball mill of the bulk Nd-Fe-B with a shaker mill. Also mechanical ball mill technique was applied to the mixture of Nd-Fe-B and Fe-B nanoparticles to build up an exchange-coupled nanocomposite magnet. It was loaded in electronic furnace and annealed under a flow of hydrogen at 953 K for 30 min. The exchange coupled interaction of isotropic magnets was characterized by smooth hysteresis loop with a high value of remanence (Mr/Ms > 0.5).
RESUMO
High temperature solution phase decomposition of Fe(CO)5 and reduction of Pt(acac)2 in the presence of stabilizers of oleic acid and oleyl amine are employed to produce Fe(1-x)Pt(x) alloy nanoparticles. The Fe and Pt composition of the nanosized materials can be tuned by adjusting the molar ratio of Fe(CO)5 to Pt(acac)2, and the compositions ranging from Fe40Pt60 to Fe80Pt20 are obtained. This study is to investigate the influence of the composition on Curie temperature (Tc) of Fe(1-x)Pt(x) nanoparticles monitored by thermomagnetic analysis (TMA).
