Semi-Empirical Force-Field Model for the Ti1-xAlxN (0 ≤ x ≤ 1) System

G A Almyras; D G Sangiovanni; K Sarakinos

doi:10.3390/ma12020215

Semi-Empirical Force-Field Model for the Ti_1-xAl_xN (0 ≤ x ≤ 1) System

Materials (Basel). 2019 Jan 10;12(2):215. doi: 10.3390/ma12020215.

Authors

G A Almyras¹, D G Sangiovanni^{2

3}, K Sarakinos⁴

Affiliations

¹ Nanoscale Engineering Division, Department of Physics, Chemistry, and Biology, Linköping University, SE 581 83 Linköping, Sweden. george.almyras@gmail.com.
² Atomistic Modelling and Simulation, ICAMS, Ruhr-Universität Bochum, D-44801 Bochum, Germany. davide.sangiovanni@liu.se.
³ Theoretical Physics Division, Department of Physics, Chemistry, and Biology, Linköping University, SE 581 83 Linköping, Sweden. davide.sangiovanni@liu.se.
⁴ Nanoscale Engineering Division, Department of Physics, Chemistry, and Biology, Linköping University, SE 581 83 Linköping, Sweden. kostas.sarakinos@liu.se.

Abstract

We present a modified embedded atom method (MEAM) semi-empirical force-field model for the Ti_1-xAl_xN (0 ≤ x ≤ 1) alloy system. The MEAM parameters, determined via an adaptive simulated-annealing (ASA) minimization scheme, optimize the model's predictions with respect to 0 K equilibrium volumes, elastic constants, cohesive energies, enthalpies of mixing, and point-defect formation energies, for a set of ≈40 elemental, binary, and ternary Ti-Al-N structures and configurations. Subsequently, the reliability of the model is thoroughly verified against known finite-temperature thermodynamic and kinetic properties of key binary Ti-N and Al-N phases, as well as properties of Ti_1-xAl_xN (0 < x < 1) alloys. The successful outcome of the validation underscores the transferability of our model, opening the way for large-scale molecular dynamics simulations of, e.g., phase evolution, interfacial processes, and mechanical response in Ti-Al-N-based alloys, superlattices, and nanostructures.

Keywords: MD simulations, molecular dynamics; MEAM; Ti-Al-N; force-field model; interatomic potential; phase stability; spinodal decomposition; titanium-aluminum nitride.