Magnetic hardening in SmCox-Co multilayers and nanocomposites

SmCox-Co (x=3.5, 4, and 5) nanostructured multilayers have been prepared by dc and rf sputtering. Magnetic hardening has been found in the as-deposite d thin films. The effects of the Co and hard-phase layer thicknesses and th e effect of the Cr underlayer have been studied. Further magnetic hardening has been achieved by heat treating the samples. A remarkable increase of t he coercivity has been obtained in the nanocomposite films, with coercive f orce up to 40 kOe. Transmission electron microscopy, atomic force microscop y, and magnetic force microscopy observations have been performed to unders tand the nanostructure and the domain structure. (C) 1999 American Institut e of Physics. [S0021-8979(99)61208-7].