서강대학교

초록

In this study, synthesis recycling and crystal structure of the RE (RE= Rare earth elements) based magnets has been studied. Two recycling methods for the Nd2Fe14B type magnets has been reported. In one method selective co-precipitation and in the other method direct annealing method has been employed. Removal of CaO byproduct by ball milling in ethanol and washing in glove box improved the magnetic properties significantly. Synthesis of the Nd2Fe14 B type magnets is a complicated, time and consuming process. Hence, a simple method for the synthesis of these particles from the magnetic precursors has been reported. Process consists of the leaching, roasting, solvent extraction and reduction-diffusion steps. Furthermore, accurate site for the Dy substitution in the (Nd-Dy)2Fe14B magnets has been determined. HAADF-STEM analysis confirmed that Dy substitutes the Nd at "f" site in the crystal structure. SmCo5-xCux particles were prepared by reduction-diffusion process. Cu substituted the Co at "2c" sites, which reduced magnetic properties moment, enhanced anisotropy energy and coercivity. Cu is six times cheaper than Co reduced the cost of the produced magnetic particles