Temperature dependence of magnetocrystalline anisotropy energy determined using Co-Cr-Ta single crystal thin films

The composition and temperature dependencies of uniaxial magnetocrystalline anisotropy constants K_u1 and K_u2 are investigated by torque magnetometry for (101¯0)-oriented Co_96-xCr_xTa₄ single crystal thin films (x=8-19 at.%). The K_u1 and the Ku _u2 values of Co₈₈Cr₈Ta₄ are determined at 290 K to be 2.2×10⁶ and 5.9×10⁵ erg/cm3, 6.9×10⁵ and 5.3×10⁴ erg/cm³, respectively, with increasing Cr concentration from 8 to 19 at.%. When the temperature is increased from 290 to 450 K, K_u1 of Co₈₈Cr₈ Ta₄ thin films decreases by 27% to 1.6×10⁶ erg/cm³. The temperature dependencies of K_u1 and K_u2 increase with increasing Cr content in Co-Cr-Ta films. The compositional and the temperature dependencies of K _u1 and K_u2 are related to the decrease in Curie temperature of Co-Cr-Ta material with increasing Cr concentration