Magnetic anisotropy and damping in epitaxial Fe-Co-Ni binary and ternary alloy thin films

• The region where the magneto-crystalline anisotropy constant K 1 > 0 extended further on the Ni-rich side than in bulk. • Uniaxial magnetic anisotropy on the order of 10 3 erg/cc was manifested in all the films. • The composition dependence of magnetic damping constant α is closely aligned with the behavior predicted by the Kamberský model. We deposited epitaxial thin films of typical ferromagnetic Fe-Co-Ni alloys with various compositions on MgO (001) single crystal substrate by sputtering and then systematically investigated their magnetic anisotropy and magnetic damping constant α . The results showed that the magneto-crystalline anisotropy constant K 1 roughly reproduced the composition dependence of bulk single crystals, but the region with K 1 > 0 extended further on the Ni-rich side compared to the bulk’s. Additionally, uniaxial magnetic anisotropy on the order of 10 3 erg/cc was manifested in all the films. Regarding α , larger values were observed on the Ni-rich alloys, with a tendency to decrease with the addition of Fe or Co. Furthermore, the compositional dependence of α was found to replicate the behavior predicted by the Kamberský model.