First-principles study of structural and elastic properties of Sc₂AC (A=Al, Ga, In, Tl)

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• 作者：A. Bouhemadou ; R. Khenata ; M. Kharoubi ; Y. Medkour
• 关键词：A. MAX phases ; B. Ab initio ; C. Pressure effect ; D. Structural properties
• 刊名：Solid State Communications
• 出版年：2008
• 期刊代码：101_00381098
• 类别：ms
• 出版时间：April 2008
• 卷：146
• 期：3-4
• 页码：175-180
• 文件大小：735 K

摘要

Using first-principles calculations, the structural and elastic properties of Sc₂AC, with A=Al, Ga, In and Tl, were studied by means of the pseudo-potential plane-waves method. Calculations were performed within the local density approximation to the exchange-correlation approximation energy. The effect of high pressures, up to 20 GPa, on the lattice constants and the internal parameters is calculated. The elastic constants are calculated using the static finite strain technique. We derived the bulk and shear moduli, Young’s moduli and Poisson’s ratio for ideal polycrystalline Sc₂AC aggregates. We estimated the Debye temperature of Sc₂AC from the average sound velocity. This is the first quantitative theoretical prediction of the elastic properties of Sc₂AlC, Sc₂GaC, Sc₂InC and Sc₂TlC compounds, and it still awaits the experimental confirmation.