Title:	Temperature-dependent properties of transition metal nitrides and carbides via equilibrium and non-equilibrium quantum molecular dynamics
DNr:	SNIC 2016/1-431
Project Type:	SNIC Medium Compute
Principal Investigator:	Valeriu Chirita <vio@ifm.liu.se>
Affiliation:	Linköpings universitet
Duration:	2016-11-01 – 2017-11-01
Classification:	20501
Keywords:

Abstract

We use density-functional-based ab initio molecular dynamics (AIMD) to determine the electronic and mechanical properties of transition metal nitrides and carbides as a function of temperature. Given the limitations on the time-scales accessible via highly computationally-demanding AIMD simulations, a non-equilibrium technique (accelerated AIMD) that we have recently developed is employed to efficiently achieve accurate quantitative evaluation of the rate of rare events, such as dislocation glide and point-defect formation and migration. We are currently modelling crack formation, dislocation glide, nanoindentation and compression of nanopillars for transition metal nitride and carbide systems via AIMD. Using the resources provided by SNIC, during 2015 and 2016 we have published 11 papers in peer-reviewed journals and one Master Thesis. D. Edstrom is close to defend is PhD Thesis (Nov. 2016), which is entirely based on results collected using SNIC resources. 1. Mei, Hellman, Sangiovanni, Alling, Hultman, Petrov, Greene Dynamic and structural stability of cubic vanadium nitride Physical Review B 91, 054101 (2015) 2. Sangiovanni, Alling, Hultman, Abrikosov Nitrogen vacancy, self-interstitial diffusion, and Frenkel-pair formation/dissociation in B1 TiN studied by ab initio and classical molecular dynamics with optimized potentials Physical Review B 91, 054301 (2015) 3. Edström, Sangiovanni, Hultman, Petrov, Greene, Chirita The dynamics of TiNx (x = 1–3) admolecule interlayer and intralayer transport on TiN/TiN(001) islands Thin Solid Films 589, 133 (2015) 4. Mei, Hellman, Hultman, Petrov, Greene Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations Phys. Rev. B 92, 174301 (2015) 5. Sangiovanni, Hultman, Chirita, Petrov, Greene Effects of phase stability, lattice ordering, and electron density on plastic deformation in cubic TiWN pseudobinary transition-metal nitride alloys Acta Materialia 103, 823 (2016) 6. Sangiovanni, Hultman, Petrov, Greene, Chirita N and Ti adatom dynamics on stoichiometric polar TiN(111) surfaces Surface Science 249, 72 (2016) 7. Sangiovanni, Hellman, Alling, Abrikosov Efficient and accurate determination of lattice-vacancy diffusion coefficients via non equilibrium ab initio molecular dynamics Physical Review B 93, 094305 (2016) 8. Sangiovanni, Mei, Hultman, Chirita, Petrov, Greene Ab initio molecular dynamics simulations of nitrogen/VN(001) surface reactions: vacancy-catalyzed N2 dissociative chemisorption, N adatom migration, and N2 desorption The Journal of Physical Chemistry C 120, 12503 (2016) 9. Edström, Sangiovanni, Hultman, Petrov, Greene, Chirita Large-scale molecular dynamics simulations of TiN/TiN(001) epitaxial film growth Journal of Vacuum Science & Technology A 34, 041509 (2016) 10. Mei, Tuteja, Sangiovanni, Hultman, Petrov, Greene Growth, nanostructure, and optical properties of epitaxial VNx/MgO(001) (0.80 ≤ x ≤ 1.00) layers deposited by reactive magnetron sputtering Journal of Materials Chemistry C 4, 7924 (2016) 11. Mikula, Sangiovanni, Čaplovič, Plecenik, Kúš Toughness enhancement in highly NbN-alloyed Ti-Al-N hard coatings Acta Materialia 121, 59 (2016) 12. Gambino Examensarbete LITH-IFM-A-EX—16/3248—SE “Titanium vacancy diffusion in TiN via non-equilibrium ab initio molecular dynamics”, 2016