Speaker
Description
Tuning Soft Magnetic Properties in Fe-Based Nanocrystalline Alloys via Ge Substitution
Paul White, Department of Physics
Tula R. Paudel, Department of Physics
Soft magnetic materials play a crucial role in modern electrical and electronic devices, with ongoing research focused on enhancing their performance through compositional and structural modifications. In this study, we investigate Fe-based nanocrystalline alloys with Ge substitution for Si to improve their magnetic properties. Using a combination of experimental techniques and density functional theory (DFT) calculations, we explore the structural evolution, phase formation, and magnetization behavior of Fe72Nb4Cu1Si16-xGexB7 (x=0-16) alloys. Melt-spin casting was used to synthesize amorphous ribbons and isothermal annealing at 525°C for 30 min was used to grow nanocrystals which are surrounded by a residual amorphous matrix. X-ray diffraction (XRD) was performed on the as-cast samples to ensure amorphousness and on the nanocomposites to identify the crystalline phase. The shift in the primary XRD peak indicates that Ge substitutes for Si in the nanocrystals forming the Fe3Si1-yGey phase. Vibrating sample magnetometry measurements determined the magnetic saturation and coercivity of amorphous and nanocrystalline samples. Density functional theory calculations were able to explain the increase in magnetization through an increase in p-d hybridization with Ge-Fe compared to Si-Fe. Our findings demonstrate that Fe72Nb4Cu1Si16-xGexB7 (x=0-16) alloys exhibit enhanced magnetic saturation and small coercivity, highlighting their potential as improved alternatives to existing soft magnetic materials.
