Abstract Scope |
Employing electronic-structure theory, we identify the weakly localized nature of cobalt in CeCo5, which causes high uniaxial magnetic anisotropy of ~ 10 MJ/m3. In contrast, substituted Cu delocalizes the Co’s 3d-states, resulting in lower anisotropy. Calculations show that 10% Cu can stabilize 20% Fe replaced for the Co, which significantly enhances magnetic moment in the Ce (Co, Fe, Cu)5. This prediction is in good agreement with a single-crystal experiment in which the best optimal composition was identified to be 15% of Fe and 12% Cu. The competitive Co sites preferred by Cu and Fe, a unique electronic-structure including exchange and crystal field splitting, and rigid-band shift variation are borne by 3d states of Co, Fe, and Cu around the Fermi level, all play an essential role in tuning the magnetic properties.
This work is supported by CMI, an Energy Innovation Hub, funded by the USDOE, Office of EERE, AMO. |