First-principles investigation on the atomic structure, stability and electronic property of O(001)/132(110) interface in Ti2AlNb alloys

摘要

In the present work, first-principles calculation is employed to investigate the adhesion, stability and electronic property of Ti(2)ALNb O(001)/62(110) interface. It is found that the Ti2AlNb O(001) surface slab and B2(110) surface slab can reach bulk-like characteristics when the atomic layers are larger than seven. Four kinds of Ti(2)ALNb O(001)/62(110) interfacial models are investigated in consideration of different interfacial atom stacking sites. The adhesive work, interfacial energy and electronic structure of these four interface models are calculated. The results show that the Ti(2)ALNb O(001)/62(110) interface with the bridge-stacking site 1, i.e. the interfacial atoms of O phase are located either between Al and Nb atoms or between two Ti atoms on the first atomic layer of B2(110) surface slab, shows the smallest interface distance (2.34 angstrom), the largest adhesion work (3.38 J/m(2)) and the lowest interface energy (0.411/m(2)), which indicates that this interfacial configuration is the most thermodynamically stable and is preferred equilibrium structure for the Ti(2)ALNb O(001)/62(110) interface. The calculated electronic properties reveal that the maximum thermodynamic stability of Ti(2)ALNb O(001)/62(110) interface with the bridge-stacking site 1 is mainly contributed from Ti-Nb covalent and Ti-Al covalent interactions. (C) 2019 Elsevier B.V. All rights reserved.