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

Abstract

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 (CH3CN) 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.