Title:	Temperature-dependent properties of transition metal nitrides and carbides via equilibrium and non-equilibrium quantum molecular dynamics
DNr:	SNIC 2018/3-478
Project Type:	SNIC Medium Compute
Principal Investigator:	Valeriu Chirita <vio@ifm.liu.se>
Affiliation:	Linköpings universitet
Duration:	2018-11-01 – 2019-11-01
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 2017 and 2018 we have published 10 papers in peer-reviewed journals. SNIC resources have been employed for all these projects and acknowledged in all publications. Other four manuscripts are currently under review in ACS Nano, Physical Review Letters, Physical Review B, and Physical Review Materials 1. Edström, Sangiovanni, Hultman, Petrov, Greene, Chirita Effects of incident N atom kinetic energy on TiN/TiN(001) film growth dynamics: A molecular dynamics investigation Journal of Applied Physics 121, 025302 (2017) 2. Mikula, Sangiovanni, et al. Thermally induced age hardening in tough Ta-Al-N coatings via spinodal decomposition Journal of Applied Physics 121, 155304 (2017) 3. Mikula, Truchlý, Sangiovanni, et al. Experimental and computational studies on toughness enhancement in Ti-Al-Ta-N quaternaries Journal of Vacuum Science & Technology A 35, 060602 (2017) 4. Gambino, Sangiovanni, Alling, Abrikosov Nonequilibrium ab initio molecular dynamics determination of Ti monovacancy migration rates in B1 TiN Physical Review B 96, 104306 (2017) 5. Zheng, Mei, Tuteja, Sangiovanni, et al. Phonon and electron contributions to the thermal conductivity of VNx epitaxial layers Physical Review Materials 1, 065002 (2017) 6. Edström, Sangiovanni, Hultman, Petrov, Greene, Chirita Elastic properties and plastic deformation of TiC- and VC-based pseudobinary alloys Acta Materialia 144, 376 (2018) 7. Sangiovanni, Mei, Edström, Hultman, Chirita, et al. Effects of surface vibrations on interlayer mass transport: Ab initio molecular dynamics investigation of Ti adatom descent pathways and rates from TiN/TiN(001) islands Physical Review B 97, 035406 (2018) 8. Sangiovanni Inherent toughness and fracture mechanisms of refractory transition-metal nitrides via density-functional molecular dynamics Acta Materialia 151, 11 (2018) 9. Sangiovanni Copper adatom, admolecule transport, and island nucleation on TiN(001) via ab initio molecular dynamics Applied Surface Science 450, 180 (2018) 10. Sangiovanni, Gueorguiev, Kakanakova-Georgieva Ab initio molecular dynamics of atomic-scale surface reactions: insights into metal-organic chemical vapor deposition of AlN on graphene Physical Chemistry Chemical Physics 20, 17751 (2018)