Magnetic and Magnetoresistive Properties of Au/Co Superlattices

Au/Co artificial superstructure films were prepared by an alternating deposition technique in ultra-high vacuum. A large perpendicular anisotropy was found to occur when the Co layers were thinner than 20 Ã…. From torque measurements the maximum value of K¿ at room temperature was estimated to be 9.6 × 10⁶ erg/cm³. The surface anisotropy energy constant Ks was about 0.4 erg/cm². The magnetoresistivity was measured as a function of a perpendicular applied magnetic field. The magnetoresistivity curve obtained was hysteretic, showing a peak in the vicinity of Hc. The maximum change in resistivity was about 4% at 77 K.