Elastic,mechanical, electronic,and defective properties of Zr–Al–C nanolaminates from first principles |
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Authors: | Changying Wang Han Han Yuanyuan Zhao Wei Zhang Yongliang Guo Cuilan Ren Guangli Zeng Qing Huang Ping Huai |
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Affiliation: | 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China;2. Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas;3. Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials (FiNE), Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China |
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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)nAl3C2 (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)nAl4C3 (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 Zr2AlC < Zr3AlC2 < Zr2Al4C5 < Zr3Al4C6 < Zr2Al3C4 < Zr3Al3C5 < Zr4Al3C6. The (ZrC)nAl3C2 (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 Zr2AlC and Zr3AlC2, 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 VZr and VAl increases, while the formation energy of VC decreases. |
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Keywords: | elastic constants electrical properties first principles theory MAX phases |
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