Microwave-Based Chemical Synthesis of Co-Alloyed Nd-Fe-B Hard Magnetic Powders

摘要: Modern high-energy-product permanent magnets derive their superior properties from nanoscale interactions, which are a sensitive function of the crystal size. Further property improvements require novel synthesis techniques to control Hence, we report cost-effective and facile technique, i.e., microwave-based synthesis, produce Co-alloyed Nd-Fe-B-based magnetic nanostructured powder. Dedicated microwave equipment with an optical pyrometer attachment was used synthesize mixed metal oxides, followed by reduction diffusion Nd-Fe-Co-B nanoparticles. Nanosized oxide powders were formed in single-step combustion after ignition, completed within few seconds. In process, two-step reaction observed. Co Fe oxides first reduced as temperature reached $350\, ^\circ {\text{C}}$ . Nd partially ${\text{NdH}}_{\text{2}}$ at ${350\, \text{C}}$ finally when ${740\, , desired ${\text{Nd}}_{\text{2}}{\text{(Fe,Co)}}_{\text{14}}{\text{B}}$ phase also obtained. This sequence matched thermodynamic calculations. Microwave power played crucial role controlling temperature, size, coercivity The these nanoparticles increased 4.6kOe 8kOe mean size 20 60nm. saturation magnetization 106emug.