Investigating the effect of nitrogen on the structural and tribo-mechanical behavior of vanadium nitride thin films deposited using R.F. magnetron sputtering

Abstract

Magnetron sputtering is one of the most commonly used deposition techniques, which has received considerable attention in industrial applications. In particular, owing to its compatibility with conventional fabrication processes, it can produce and fabricate high-quality dense thin films of a wide range of materials. In the present study, nitrogen (N) was combined with pure vanadium in order to form binary nitride to improve its mechanical and tribological performance. To evaluate the influence of nitrogen on the structure of the as-deposited vanadium nitride (VN) coatings, the following techniques were used: XPS, XRD, SEM, AFM and optical profilometry. The residual stresses were determined by the curvature method using Stoney’s formula. The hardness and Young’s modulus were obtained by nanoindentation measurements. The friction behavior and wear characteristics of the films were evaluated by using a ball-on-disk tribometer. The obtained results showed that the N/V ratio increased with increasing the N2 flow rate while the deposition rate decreased. The preferred orientation was changed from (200) to (111) as the N2 flow rate increased with the presence of V–N and V–O binding energies as confirmed by XPS analysis. The nitrogen addition resulted in a columnar morphology and a fine structure with fine surface roughness. The VN thin film containing 49.5 at.% of nitrogen showed the best performance: highest mechanical properties (hardness = 25 GPa), lowest friction coefficient (μ = 0.37) and lowest wear rate (Ws = 2.72 × 10−5 mm3N−1 m−1). A good correlation between the film microstructure, crystallite size, residual stress and mechanical and tribological properties was observed.

Major Improvement in the Cycling Ability of Pseudocapacitive Vanadium Nitride Films for Micro‐Supercapacitor

“…We clearly see a strong evolution of the preferred orientation with both the pressure and the N 2 ratio, as already reported in the literature for tribological issues of VN coatings, not used for their electrochemical properties but for their attractive hardness properties. [46,56] The Figure 5a summarizes the evolution of the ratio between the intensity of the (111) versus the (200) Bragg peaks regarding the N 2 content in total gas and the deposition pressure. We observe that this ratio progressively decreases and converges toward the theoretical ratio issued from JCPDS card (VN powder, 36-0768) meaning that the VN film is approaching the VN bulk free powder behavior.…”

Magnetron Sputtered Thin Films Based on Transition Metal Nitride: Structure and Properties

“…Linda Aissani et al [ 112 ] investigated the effect of N 2 on tribomechanical and structural properties using an RF magnetron sputtering system. As the percentage of N 2 increased 1) the composition of coating transformed from the mixture of phases (V 2 N and VN) to the pure VN phase; 2) a smooth film surface with fine grains appeared; 3) the average surface roughness reduced from 25 to 6 nm; and 4) the average friction coefficient value of the films got reduced from 0.61 to 0.37.…”

“…Effect of N 2 flow rate on a) hardness and Young's modulus b) wear rate of VN thin films deposited using RF magnetron sputtering at a power density of 6.23 W cm 2 . [ 112 ] …”

“…Effect of N 2 flow rate on a) hardness and Young's modulus b) wear rate of VN thin films deposited using RF magnetron sputtering at a power density of 6.23 W cm 2 . [112] In addition, another study was carried out to know the influence of VN film thickness on the performance of the coating by using the magnetron sputtering technique. The results concluded that as the film thickness increased, the crystallites were refined enhancing the coating, building strong adhesion, and increased plastic deformation resistance.…”

Combinatorial Reactive Sputtering with Auger Parameter Analysis Enables Synthesis of Wurtzite Zn2TaN3

“…33 Second, the films might exhibit low crystallinity due to cation/anion off-stoichiometry. 34 This is especially challenging since common high-throughput methods for composition analysis, such as conventional energy-dispersive (ED) XRF, have limitations regarding the quantification of nitrogen owing to its low atomic mass. Third, high-throughput XRD screening of samples with preferential out-of-plane orientation can complicate phase identification when grains are aligned out of the diffraction plane.…”