In this work, we studied the energetics of diffusion-related quantities of transition-metal impurities in TiN, a prototype ceramic protective coating. We use ab-initio calculations to construct a database of impurity formation energies, vacancy-impurity binding energies, migration, and activation energies of 3d and selected 4d and 5d elements for the vacancy-mediated diffusion process. The obtained trends suggest that the trends in migration and activation energies are not fully anti-correlated with the size of the migration atom. We argue that this is caused by a strong impact of chemistry in terms of binding. We quantified this effect for selected cases using the density of electronic states, Crystal Orbital Hamiltonian Population analysis, and charge density analysis. Our results show that the bonding of impurities in the initial state of a diffusion jump (equilibrium lattice position), as well as the charge directionality at the transition state (energy maximum along the diffusion jump pathway), significantly impact the activation energies.
|Scientific reports (London : Nature Publishing Group)
|Veröffentlicht - 22 Mai 2023
Bibliographische NotizFunding Information:
GKN and DH highly acknowledge the financial support through the joint project of the Austrian Science Fund (FWF, project number I 4059-N36) and the Czech Science Foundation (project number 19-29679L). MZ highly acknowledges the financial support through the Operational Program Research, Development and Education financed by the European Structural and Investment Funds and the Czech Ministry of Education, Youth and Sports (MEYS CR) [project MATFUN CZ.02.1.01/0.0/0.0/15 003/0000487] and Brno University of Technology [project number FSI-S-20-6313]. The computational results presented have been partially achieved using the Vienna Scientific Cluster (VSC).
© 2023, The Author(s).