Structural, elastic and electronic properties of C14-type Al₂M (M=Mg, Ca, Sr and Ba) Laves phases

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• 作者：Ma Lishi ; Duan Yonghua ; ^{duanyh@kmust.edu.cn} ; Li Runyue
• 关键词：First-principles calculations ; Phase stability ; Elastic properties ; Anisotropy ; Electronic structures
• 刊名：Physica B: Condensed Matter
• 出版年：2017
• 出版时间：15 February 2017
• 年：2017
• 卷：507
• 期：Complete
• 页码：147-155
• 全文大小：935 K
• 卷排序：507

文摘

The structural and mechanical properties, Debye temperatures and anisotropic sound velocities of the Laves phases Al2M (M=Mg, Ca, Sr and Ba) with C14-type structure were investigated using the first-principles corresponding calculations. The corresponding calculated structural parameters and formation enthalpies are in good agreement with the available theoretical values, and Al2Ca has the best phase stability. The mechanical properties, including elastic constants, bulk modulus B, shear modulus G, Young’s modulus E, and Poisson ratio ν, were deduced within the Voigt-Reuss-Hill approximation. The brittleness and ductility were estimated by the values of Poisson ratio, B/G and Cauchy pressure. Moreover, the elastic anisotropy was investigated by calculating and discussing several anisotropy indexes. Finally, the electronic structures were used to illustrate the bonding characteristics of C14-Al2M (M=Mg, Ca, Sr and Ba) phases.