Phase evolution and magnetic properties of (Ce,Nd)-Fe-B prepared using microwave-assisted approach.

A bottom-up synthesis strategy combining microwave-assisted oxide formation with a reduction-diffusion process has been developed to produce (Ce,Nd)-Fe-B powders. A full compositional range from 0 to 100% Ce was successfully synthesized, and a detailed investigation of phase evolution of the oxides and alloys as a function of Ce concentration was studied, and the reduction diffusion mechanism was also identified. Powder XRD, thermal analysis and TEM confirm the formation of a (Ce,Nd)2Fe14B phase and show nanostructure features. The coercivity of the nanoparticles varied from 0.4 to 9.1 kOe depending on the composition of Ce-Nd-Fe-B, which is related to the intrinsic magnetic properties of (Ce,Nd)2Fe14B with different Ce content and the formation of secondary phases. Additionally, coercivity was improved in Ce-Fe-B particles doped with Cu, Al, Pr, Dy, and Nd.