Crystal structure of Co/Cu multilayers prepared by pulse potential electrodeposition with precisely controlled ultrathin layer thickness

Co/Cu multilayers were electrodeposited in a single electrolyte using the pulse potential method and the layer thickness was precisely controlled in accordance with Faraday's law. X-ray diffraction revealed that multilayers with layer thicknesses in the range of 25–100 nm consisted of fcc-Co and fcc-Cu phases. For layers thinner than 10 nm, the fcc-Co and fcc-Cu phases merged to form a single crystal phase. When the layers were <1 nm, one diffraction peak of the single crystal phase became proportionally higher as the layer became thinner. The surface structure of multilayers also varied with the layer thickness.