Temperature Dependence of the Uniaxial Magneto-Crystalline Anisotropy Energy of Co

Torque measurements have been made for a thin disc specimen of Co of which the disc plane was parallel to the (1010) plane at various temperatures between 4.2 K and the room temperature in an external magnetic field of 16.9 kOe which was strong enough to saturate the magnetization. The obtained values of K u 1 and K u 2 were in good agreement with those obtained by Rebouillat and Sucksmith and Thompson. The temperature dependence of K u 1 below about 200 K could well be explained with a model based on the itinerant electron theory by considering the thermal expansion of the lattice parameter ratio.