A New Role of M1 Type Dopant for Nd-Rich Nd-Fe-Co-B Nanocrystalline Ribbons

In this work, our attempts focused on Ge effects on magnetic-microstructural relationships in Nd-Fe-Co-B nanocrystalline ribbons. Based on Transmission Electron Microscopy (TEM) and three dimensional atom probe (3DAP) analysis, it was observed that Ge containing alloys have a new behavior that was not observed yet. The increase of Ge content up to 0.36at% caused the increase of Br and (BH)max due to increase of Co content of Nd2Fe14B phase. However, the magnetic properties deteriorated for Ge bearing samples beyond 0.36at% due to the decrease of volume fraction of Nd2Fe14B phase. The comparison of Ge and Ga (another M1 dopant) effects on coercivity was reported and microstructural studies (using TEM and 3DAP) were shown the Nd-rich phase morphology and its alloying elements distribution in the nanometer sized intergranular phase.