Preparation, structural and mechanical properties of electrodeposited Co/Cu multilayers

Electrodeposited Co/Cu multilayer films were grown on (001)-oriented Si and polycrystalline copper substrates by single bath technique. Several Co/Cu samples deposited with different sublayer thickness in the range of 1 to 20 nm were investigated. A series of the multilayers with varying bilayer thickness A were electrodeposited on copper substrates. The modulated structure of Co/Cu multilayer was investigated by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the multilay ered deposits have columnar structure, with various column diameters. The column diameters and the preferential crystallographic orientation depend on the total thickness of the deposit. Mechanical properties of Co/Cu multilayers were investigated by microhardness and tribological tests. It was found that hardness of the Co/Cu multilayers depend on the bilayer period and is much higher than those of Co and Cu single layer coatings. A different wear mechanism of Co/Cu multilayers for bilayer period 6, 10 and 40 nm was observed. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim