서강대학교

초록/요약

The Nd2Fe14B hard phase magnetic nanoparticles were successfully synthe-sized by chemical synthesis route followed by reduction and diffusion process without consuming a large amount of energy. Nd(acac)3·xH2O, Fe(acac)3 and (C2H5)3NBH3 were used as precursors and CaH2 was used as a reducing agent for the reduction and diffusion process. The crystal structure and compositions of resultant products were detected with XRD and energy dispersive X-ray spectrometer (EDS) measurements. The overall morphologies and magnetic properties of final products were measured with TEM and vibrating sample magnetometer (VSM) at 300 K. The effect of CaH2 quantity on magnetic prop-erties of final products was investigated with the different mixing weight ratio of CaH2 to the preliminary reduced metal oxide powders by checking with HRTEM, XRD and VSM measurements. The different mechanisms on the re-duction and diffusion process with different amount of CaH2 were compara-tively studied. Deficient amount of CaH2 resulted in the remaining unreduced metal oxide powders. This causes the low magnetic properties of final products. Excessive amount of CaH2 would decrease the magnetic properties of Nd2Fe14B magnetic nanoparticles because the formation of Nd2Fe14BHx produced by hy-drogenation of produced Nd2Fe14B nanoparticles by the evolving H2 gas during washing process of the unreacted CaH2 with water. The amount of CaH2 had a critical effect on the low magnetic properties of the products.