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 (10 (1) over bar 0)-oriented Co96-xCRxTa4 single crystal thin films (x = 8 - 19 at.%). The K-u1 and the k(u2) values of Co88Cr8Ta4 are determined at 290 K to be 2.2x10(6) and 5.9x10(5) erg/cm(3), respectively. The K-u1 and the K-u2 decrease to 6.9x10(5) and 5.3x10(4) erg/cm(3), respectively, with increasing Cr concentration from 8 by 19 at.%. When the temperature is increased from 290 to 450 K, K-u1 of Co88Cr8Ta4 thin film decreases by 27 % to 1.6x10(6) erg/cm(3). The temperature dependencies of K(u1 )and K-u2 increases 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.