First-principles investigation on the atomic structure, stability and electronic property of O(001)/B2(110) interface in Ti2AlNb alloys

• Published in: Journal of alloys and compounds 2020-03, Vol.817, p.152734, Article 152734
• Main Authors: Wang, Aiqin, Liu, Pei, Xie, Jingpei, Ma, Douqin, Mao, Zhiping
• Format: Article
• Language: English
• Subjects: Adhesion; Adhesive work; Aluminum; Atomic structure; Electronic properties; Electronic structure; First principles; First-principles calculation; Interface properties; Interface stability; Interfacial energy; Intermetallic compounds; Investigations; Niobium; Stacking; Structural stability; Thermodynamic equilibrium; Ti2AlNb alloys; Titanium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.152734

In the present work, first-principles calculation is employed to investigate the adhesion, stability and electronic property of Ti2AlNb O(001)/B2(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 Ti2AlNb O(001)/B2(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 Ti2AlNb O(001)/B2(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 Å), the largest adhesion work (3.38 J/m2) and the lowest interface energy (0.41 J/m2), which indicates that this interfacial configuration is the most thermodynamically stable and is preferred equilibrium structure for the Ti2AlNb O(001)/B2(110) interface. The calculated electronic properties reveal that the maximum thermodynamic stability of Ti2AlNb O(001)/B2(110) interface with the bridge-stacking site 1 is mainly contributed from Ti–Nb covalent and Ti–Al covalent interactions. [Display omitted] •7-layered Ti2AlNb O(001) and B2(110) surface slab can reach bulk-like characteristics.•The Ti2AlNb O(001)/B2(110) interface with the bridge-stacking site 1 is the most thermodynamically stable.•The Ti2AlNb O(001)/B2(110) interface with the bridge-stacking site 1 is a mixture of Ti-Nb and Ti-Al covalent bonds.