Temperature-dependent properties of transition metal nitrides and carbides via equilibrium and non-equilibrium quantum molecular dynamics
Title: Temperature-dependent properties of transition metal nitrides and carbides via equilibrium and non-equilibrium quantum molecular dynamics
DNr: SNIC 2015/1-393
Project Type: SNIC Medium Compute
Principal Investigator: Valeriu Chirita <vio@ifm.liu.se>
Affiliation: Linköpings universitet
Duration: 2015-11-01 – 2016-11-01
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. Since lattice vibrations strongly affect structural stability [1], lattice ordering, and reaction rates at finite temperatures [2,3], AIMD is the most reliable computational tool in determining material properties and revealing non-intuitive reaction pathways at finite temperatures [2,4]. 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 [5] is employed to efficiently achieve accurate quantitative evaluation of the rate of rare events, such as dislocation glide and point-defect formation and migration. [1] A.B. Mei, O. Hellman, N. Wireklint, C.M. Schlepütz, D.G. Sangiovanni, B. Alling, A. Rockett, L. Hultman, I. Petrov, J.E. Greene Physical Review B 91, (2015) 054101 [2] D. G. Sangiovanni, B. Alling, P. Steneteg, L. Hultman, I. A. Abrikosov Physical Review B 91, (2015) 054301 [3] D.G. Sangiovanni, D. Edström, L. Hultman, I. Petrov, J.E. Greene, V. Chirita Surface Science, 627 (2014) 34 [4] D.G.Sangiovanni, D. Edström, L. Hultman, I. Petrov, J.E. Greene, V. Chirita Surface Science, 624 (2014) 25 [5] D.G. Sangiovanni, O. Hellman, B. Alling, I.A. Abrikosov Efficient and accurate determination of lattice-vacancy diffusion coefficients via nonequilibrium ab initio molecular dynamics arXiv:1509.04487 (submitted)