The first and second-order uniaxial magnetic anisotropy constants K1 and K2 of the Sm(Fe1– xCox)12 compounds and their temperature dependence are determined by the torque magnetometry technique using the anomalous Hall effect (AHE) on epitaxially grown Sm(Fe1- xCox)12 thin films. While K1 monotonically decreases with increasing temperature regardless of the Co concentration, K2 changes its sign from negative to positive with increasing temperature and reaches a maximum at 250 K. These observations are consistent with the hard-axis magnetization curves at low temperature that show an upward deviation from a linear extrapolation of the low field part. Ab-initio estimations of the crystal field parameters at the Sm site using a spin model of Sm(Fe1– xCox)12 compounds and theoretical analysis of magnetocrystalline anisotropy of Sm3+ ions taking the multiple J-mixing into account explain these main features of the experimental results.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics