The volume and surface anisotropies of Co/Pd multilayers have been studied by ferromagnetic resonance (FMR) and vibrating sample magnetometer (VSM) measurements for different layer thicknesses and as a function of thermal treatment and before and after ion implantation. A second resonance mode was observed for some samples depending on the layer thicknesses. Exposing the samples to a thermal treatment and to Ar+-ion implantation, the observed changes of the effective anisotropy field are consistent to the idea that both processes cause a deterioration of the ML structure. No significant differences in the FMR magnetic parameters are found if the ML are grown either on glass or on Si(111) substrates apart from a change of the linewidth due to changes in texture homogeneity. (C) 1999 Elsevier Science B.V. All rights reserved.20541700161169