Polymetallic Medium-Entropy System Fe–Ni–Co–Cu Prepared via Galvanic Replacement

A fine-particle Fe–Ni–Co–Cu polymetallic system has been prepared in an aqueous solution of metal chlorides using galvanic replacement by fine-particle aluminum. The elemental and phase compositions of the synthesized powders have been determined by X-ray fluorescence analysis and X-ray diffraction. The content of elemental metals (Fe, Ni, Co, and Cu) in the deposit has been shown to reach 98 wt %. X-ray diffraction data have been used to evaluate the crystallite size (~20 nm) and unit-cell parameters of the phases identified. The powder particles have the form of spherical micron-sized skeletal structures (~75 μm in size), with a large number of nuclei 50–60 nm in size.