MAGNETIC COUPLING AND MAGNETIC-ANISOTROPY IN FE/CO AND FE/CU MULTILAYERS

Magnetisation measurements of magnetic multilayer samples of Fe/Co and Fe/Cu having equal layer thickness of Fe and Co and Fe and Cu, respectively, were carried out at room temperature using an alternating gradient force magnetometer (AGFM). Comparison of the saturation magnetisation measurements with calculated values of magnetisation indicated that the magnetic moments of the Fe layer and the Co layer are ferromagnetically coupled. Mossbauer spectroscopy studies at room temperature and at 4.2 K show that in the Fe/Cu multilayers and some of the Fe/Co multilayers the magnetic easy axis lies in the plane of sample. In several other Fe/Co multilayers a normal component of magnetisation is observed and it is necessary to introduce a magnetic anisotropy term favouring a magnetic easy axis normal to the sample plane. Measurements of hysteresis cycles and applied field Mossbauer studies enable the magnetic anisotropy of the samples to be evaluated.