First-principles molecular dynamics study of the thermal stability of the BN, AlN, SiC and SiN interfacial layers in TiN-based heterostructures: Comparison with experiments

• Published in: Thin solid films 2013-10, Vol.545, p.391-400
• Main Authors: Ivashchenko, V.I., Vepřek, S.
• Format: Article
• Language: English
• Subjects: Aluminum nitride; Coatings; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Heterostructures; Materials science; Mathematical analysis; Molecular dynamics; Nanocomposites; Nanostructure; Other semiconductors; Physical properties of thin films, nonelectronic; Physics; Silicon carbide; Specific materials; Stability; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theoretical calculations; Thermal stability; Thermal stability; thermal effects; TiN–AlN; TiN–BN; TiN–SiC; TiN–SiN
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.08.047

We conducted first-principles molecular dynamics calculations of the stability and possible transformations of heterostructures consisting of face-centered-cubic (NaCl)-TiN(001) slabs with one monolayer thick pseudomorphically stabilized interfacial layer of B1-type BN, AlN, SiC and SiN, respectively. The calculations have been done with subsequent static relaxation of the heterostructures at temperatures between 0 and 1400K. It is shown that: i) the BN interfacial layer forms a disordered h-BN-like structure consisting of BN3 units within the whole temperature range considered; ii) the B1-AlN interfacial layer is stable within the whole temperature range; iii) the B1-SiC interfacial layer transforms into a distorted 3C–SiC(111)-like phase above 600K; and iv) the SiN interfacial layer consists of SiN4 and SiN6 units aligned along the [110] direction at room and high temperatures. Phonon calculations show that the observed modifications of the interfaces are due to the dynamical instability of the B1-type (001) and (111) interfacial layers of BN, SiC and SiN driven by soft modes within the given planes. The results, which can be understood also without the knowledge of the theoretical methods, were used to interpret the available experimental results on TiN-based heterostructures and nanocomposite coatings in order to provide guidance to the experimentalists for the preparation of better coatings. •First-principles quantum molecular dynamics studies were conducted.•TiN-based heterostructures with SiN, BN, AlN and SiC interfacial monolayers•Stability and structural transformation between 0 and 1400K have been calculated.•The results of the calculations have been compared with experiments.•It is concluded which of the systems may form stable superhard nanocomposites.