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

Abstract

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

Spontaneous Chemical Ordering in Bimetallic Nanoparticles

“…This behavior is frequently interpreted as ideal homogeneous alloying . However, the characterization of solid solutions by conventional X-ray diffraction has been critically assessed on the example of Cu–Co alloys in the form of multilayered and heterogeneous films. , It has been shown on the example of this model system that for the layer thickness of about 10 nm, the X-ray diffraction patterns merge into a single set representing the average lattice parameters defined by the overall layers composition. By definition, this average lattice spacing must vary linearly between values for pure elements with Vegard’s law dependence when the overall composition is changed, yet this average lattice spacing is nowhere physically present in the heterogeneous sample.…”

Magnetic Properties and Microstructure of Electrodeposited Co/Cu Multilayers

“…Consequently, with both polycrystalline and multilayered structures present, a unique internal structure was formed in the metallic solid. As we reported earlier, 14 the Co and Cu layers in this sample ought to have grown alternately and epitaxially without misfit dislocations. The observed columnar structure in Figs.…”