Synthesis of CoCrFeMnNi High Entropy Alloy Thin Films by Pulse Electrodeposition: Part 1: Effect of Pulse Electrodeposition Parameters

CoCrFeMnNi high entropy alloy (HEAs) thin films were prepared using the pulse electrodeposition method. The films were co-deposited in an electrolyte based on an N,N-dimethylformamide—acetonitrile (CH 3 CN) organic system containing Co, Cr, Fe, Mn, and Ni chloride cations using the pulse electrodeposition method at frequencies of 2500 and 5000 Hz as well as duty cycles of 50% and 60%. The composition and morphology of the resulting thin films were studied. The energy-dispersive X-ray spectroscopy analysis revealed that all five elements were successfully co-deposited. The calculated entropy of mixing in different conditions ranged between 11.86 and 12.46 J K −1 mol −1 for a duty cycle of 60% in frequencies of 2500 and 5000 Hz, respectively, this indicates that the resulting materials are HEAs. The scanning electron microscopy investigations revealed that the prepared films at a duty cycle of 50% in frequencies of 2500 and 5000 Hz exhibit an inhomogeneous morphology with crystal clusters measuring between 330 and 399 nm. The grazing incidence X-ray diffraction patterns indicated that the as-deposited CoCrFeMnNi thin films consisted of a single face-centered-cubic structure. Graphic Abstract