We study two C(5 nm)/Co/C(5 nm) multilayer stacks with cobalt layer thicknesses of 4 and 13 nm. Structural analysis of fabricated systems reveals corresponding cobalt layers to be in amorphous (nanocrystalline) and [0001]‐textured hcp‐phase. The magnetic measurements for both systems agree well with structural data. For the amorphous cobalt layer magnetic data reveal the absence of carbides, high saturation field of 1.6 × 104 Oe and vanishing inplane coercive field. We also show that strong inplane anisotropy can be introduced into the amorphous cobalt film by controlling the process parameters of DC‐magnetron sputtering. For the textured hcp‐cobalt film we have deduced the presence of randomly close‐packed (rcp) structure. We assume this defect‐rich cobalt hcp‐phase to be responsible for the detected elimination of the out‐of‐plane magnetic anisotropy in the corresponding multilayer sample.