Novel Synthesis of Rare Earth Permanent Magnets for Energy Applications

Superior high performance permanent magnets are vital in an enormous variety of energy generation and utilization applications, they can reduce energy consumption and increase energy efficiency. There is also a sustainability and strategic need to reduce rare earth content. Hence, novel synthesis techniques were studied, advantages of chemical synthesis include facile elemental substitution and the ease of obtaining nanoparticles. Challenges arise from high reactivity and differences in electrochemical behavior. Chemical synthesis by sol-gel, autocombustion and microwave based methods were studied. In the sol-gel method, Nd-Fe-B gel was prepared and annealed to produce mixed oxide powders. Hard magnetic Nd2Fe14B nanoparticles were prepared from these oxides by three step reduction-diffusion. The Henkel plot revealed exchange coupling. The synthesis of exchange coupled 10 nm magnetic nanoparticles by glycine nitrate auto combustion, followed by reduction diffusion, was also carried out. These results and the magnetic properties will be discussed in the presentation.