Elastic, mechanical, electronic, and defective properties of Zr–Al–C nanolaminates from first principles. Issue 2 (6th October 2017)

• Record Type: Journal Article
• Authors: Wang, Changying; Han, Han; Zhao, Yuanyuan; Zhang, Wei; Guo, Yongliang; Ren, Cuilan; Zeng, Guangli; Huang, Qing; Huai, Ping
• Is Part Of: Journal of the American Ceramic Society. Volume 101:Issue 2(2018)
• Page Start: 756
• Page End: 772
• Publication Date: 2017-10-06
• Subjects: elastic constants -- electrical properties -- first principles theory -- MAX phases; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.15252
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: By means of first principles calculations, Zr–Al–C nanolaminates have been studied in the aspects of chemical bonding, elastic properties, mechanical properties, electronic structures, and vacancy stabilities. Although the investigated Zr–Al–C nanolaminates show crystallographic similarities, their predicated properties are very different. For (ZrC)n Al3 C2 (n = 2, 3, 4), the Zr–C bond adjacent to the Al–C slab with the C atom intercalated in the Zr layers is the strongest, but the one with the C atom intercalated between the Zr layer and Al layer is the weakest. In contrast, the situation for (ZrC)n Al4 C3 (n = 2, 3) is just the opposite. For Zr–Al–C nanolaminates, the calculated bulk, shear and Young's modulus increase in the sequence of Zr2 AlC < Zr3 AlC2 < Zr2 Al4 C5 < Zr3 Al4 C6 < Zr2 Al3 C4 < Zr3 Al3 C5 < Zr4 Al3 C6 . The (ZrC)n Al3 C2 (n = 2, 3, 4) series exhibit the most outstanding elastic properties. In the presence of the external pressure, the bulk and shear moduli exhibit a linear response to the pressure, except for Zr2 AlC and Zr3 AlC2, both of which belong to the so‐called MAX phases. The two materials also exhibit very distinct properties in the strain‐stress relationship, electronic structures and vacancy stabilities. As the intercalated Al layers increase, the formation energy of V Zr and V Al increases, while the formation energy of V C decreases.