Sputter deposited NbCxNy films: Effect of nitrogen content on structure and mechanical and tribological properties

Epitaxial NbC N1−(001) layers: Growth, mechanical properties, and electrical resistivity

“…Based on this argument, we expect the average elastic modulus E = 350 ± 12 GPa from the epitaxial NbC x N 1−x (001) layers with T s = 700-800°C to most correctly reflect the intrinsic value. This value is larger than the reported E = 315 ± 13 GPa for epitaxial NbN 0.98 (001) [19] and E = 162-295 GPa for nc-NbC/a-C films [24], but matches E = 346 ± 6 GPa for polycrystalline NbC 1.99 N 0.69 [37]. It is at the low end of the range reported for other epitaxial transition metal nitrides with E = 356 ± 18 GPa for ScN(001) [39], E = 405 ± 15 GPa for CrN(001) [45], E = 445 ± 38 for TiN(001) [73], E = 450 ± 9 GPa [43] for HfN(001) and 457 ± 16 GPa for TaN(001) [74].…”

“…The Nb content is nearly unaffected by T s and ranges from 47-49 at.%. That is, the layers exhibit a nearly stoichiometric anion-to-cation ratio of 1.09 ± 0.05, suggesting that they consist primarily of solid solution Nb(N,C) without considerable amorphous or graphitic C(N) inclusions that have previously been observed in polycrystalline NbC x N y layers [37]. The slight overstoichiometry can be attributed to interstitial N or C atoms and/or Nb vacancies that form due to implantation of energetic backscattered atoms and limited cation adatom mobility, respectively, similar to what has been reported for many other transition metal nitrides [44,60,61], but may also be attributed to possible carbon (or oxygen) surface contamination prior to EDS analyses.…”

“…The few reports on niobium carbonitride focus on its superconductive properties, with measured transition temperatures ranging from 13.2-17.8 K for layers that exhibit primarily a B1 crystal structure and are deposited by magnetron and ion-beam sputtering [33][34][35][36]. In a first effort to determine mechanical and tribological properties of NbC x N y , we have recently deposited polycrystalline NbC x N y films by magnetron sputtering and reported a maximum hardness H = 42.1 GPa for a NbC 1.44 N 0.44 film which contains both solid solution Nb(C,N) grains and amorphous C(N), and found that inclusion of an increasing sp 2 -graphite-like carbon phase reduces friction and wear but ultimately causes a reduction in the mechanical strength [37]. The measured mechanical properties are strongly affected by the microstructure, including grain size, residual stress, and especially inclusions of secondary phases like amorphous C and hexagonal NbN [37].…”

“…In a first effort to determine mechanical and tribological properties of NbC x N y , we have recently deposited polycrystalline NbC x N y films by magnetron sputtering and reported a maximum hardness H = 42.1 GPa for a NbC 1.44 N 0.44 film which contains both solid solution Nb(C,N) grains and amorphous C(N), and found that inclusion of an increasing sp 2 -graphite-like carbon phase reduces friction and wear but ultimately causes a reduction in the mechanical strength [37]. The measured mechanical properties are strongly affected by the microstructure, including grain size, residual stress, and especially inclusions of secondary phases like amorphous C and hexagonal NbN [37]. Therefore, in order to determine the intrinsic mechanical properties of B1-structure solid solution Nb(C, N), which is the primary phase that constitutes NbC x N y , it is the key to synthesize phase-pure singlecrystal layers.…”

Structural, Mechanical and Tribological Properties of NbCN-Ag Nanocomposite Films Deposited by Reactive Magnetron Sputtering

“…For example, TiCN films were prepared by Cheng et al [4], which outperformed TiN in tribological applications associated with carbon incorporation [5]. In addition, CrCN coating produced by the cathodic arc evaporation (CAE) deposition method showed higher hardness and tribological properties than CrN coatings [6].…”