Abstract: Starting from solid-solutions (SS) of AlCoCrFeNix high-entropy alloys (HEAs) that have
been produced with high purity constituent elements by vacuum arc remelting (VAR) method varying
the nickel molar ratio x from 0.2 to 2.0, we investigated the synthesis of protective thin films of HEAs
and high-entropy nitrides (HENs) with the aid of the pulsed laser deposition (PLD) system. The
structure of all ten available bulk targets have been examined by means of X-Ray Diffraction (XRD), as
well as their elemental composition by means of energy dispersion X-ray spectroscopy (EDS). Three
targets with nickel molar composition x = 0.4, 1.2 and 2.0 corresponding to BCC, mixed BCC and
FCC, and finally FCC structures were used for thin film depositions using a KrF excimer laser. The
depositions were performed in residual low vacuum (10?7 mbar) and under N2
(10-4 mbar) at room temperature (RT~25ºC) on Si and glass substrates. The deposited films'structure was investigated using grazing incidence XRD, their surface morphology, thickness and elemental composition by
scanning electron microscopy (SEM), EDS and X-ray photoelectron spectroscopy (XPS), respectively.
A homemade four-point probe (4PP) set-up was applied to determine layers electrical resistance.
Besides, a Nanoindentation (NI) was employed to test films'mechanical properties. XRD results
showed that all deposited films, regardless of the initial structure of targets, were a mixture of FCC
and BCC structures. Additionally, the quantitative and qualitative EDS and XPS results showed that
the elemental composition of films was rather close to that of the targets. The depositions under an
N2 atmosphere resulted in the inclusion of several percentage nitrogen atoms in a metallic nitride
type compound into films, which may explain their higher electrical resistivity. The Young's modulus,
nanohardness and friction coefficient values showed that the deposited films present good mechanical
properties and could be used as protective coatings to prevent damage in harsh environments.
