Abstract
Multicomponent TixNbCrAl nitride films were deposited on Si(100) substrates by reactive direct current magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) in the absence of substrate heating and bias. Three single Ti, Nb, and Cr50Al50 targets were either driven by three dc or three HiPIMS power supplies. The Ti content in the films was varied by tuning the power applied to the Ti target. The composition was determined by ion beam analysis. The nitrogen content is nearly stoichiometric (48–50 at.%) in the HiPIMS series, while the dcMS are understoichiometric (39–45 at.%). The crystal structure, stress and density of the studied film were investigated by X-ray techniques and the microstructure was examined by scanning electron microscopy. All the Ti-containing films for both series exhibit an fcc NaCl-type phase structure. In particular, the dcMS series shows a (111) preferred orientation, resulting in a faceted surface morphology compared to a dense and smooth microstructure of the HiPIMS films. The compressive stress of the HiPIMS series (> 2.0 GPa) is significantly larger than the values of the dcMS series (<0.5 GPa). Nanoindentation measurements show a maximum hardness of 29.9 GPa and Young's modulus of 304 GPa were obtained in the HiPIMS series. The results may promote HiPIMS techniques for the synthesis of complex multicomponent films for the application aspect to protective and hard coatings.
Highlights
The concept of high-entropy alloys [1,2], originally referring to a class of materials that contain five or more elements in near-equal proportions, has been rapidly extended to high entropy ceramics by replacing or adding a non-metal element
The deposition rate of the direct current magnetron sputtering (dcMS) series significantly increased from 11 to 30 nm/min, whereas that of the high power impulse magnetron sputtering (HiPIMS) series increased slightly to 10 nm/min when the power applied to the Ti target reached 270 W
Chemical composition of the TixNbCrAl nitride films deposited by dcMS and HiPIMS was determined by ToF-ERDA (Fig. 2), in good agreement with the results from Rutherford backscattering spectrometry (RBS) measurements for selected samples (Table SI. 1)
Summary
The concept of high-entropy alloys [1,2], originally referring to a class of materials that contain five or more elements in near-equal proportions, has been rapidly extended to high entropy ceramics by replacing or adding a non-metal element. (HfTaTiVZr)N films have been shown to exhibit high hardness up to 34.0 GPa while retaining a single fcc structure up to 1300 ◦C [10], which is promising for prolonging the lifetime of cutting tools Another example are (TiNbZrTa)Nx films, which exhibited a low corrosion current density (10− 8– 10− 7 A/cm2) in sulfuric acid solution, which makes them suitable for anticorrosive coating applications [11]. The significant ionization of the deposition flux re sults in a number of desirable properties of the produced thin films, such as improved film surface smoothness and increased film density [17,18,19] It has enabled the control over phase composition and microstructure as well as enhanced mechanical properties [20]. Nb is believed to improve corrosion resistance, as shown in previous works on TiNbZrTa nitrides [9,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
