A new method for analyzing torque curves of uniaxial anisotropic materials

The authors present a simple analytic method to determine the intrinsic anisotropy energy K_u and the easy axis orientation δ of a magnetic film having a uniaxial anisotropy, using a measured torque curve. Analytical expressions for K_u and δ are explicitly derived using the peak value in the measured torque curve and the angle where the torque is zero. The authors confirmed that the experimental torque curves of TbFe thin films prepared at oblique incidence match well to the theoretical curves within 10% accuracy