First-Principles Calculations on Structure,Elastic and Thermodynamic Properties of Al2X （X=Sc,Y） under Pressure
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2012年第2期
论文作者：Yasemin ztekin iftci Kemal olakoglu
文章页码：155 - 163
摘 要：To understand deeply the structural,elastic and thermodynamic characteristics of Al 2 X （X= Sc,Y） compounds in C15 type （space number 227） Cu 2 Mg structure,we have performed ab-initio density functional theory within the local density approximation （LDA） and the generalized gradient approximation （GGA）.The thermodynamic properties of the considered structures are obtained through the quasi-harmonic Debye model.We have presented the results on the basic physical parameters,such as the lattice constant,bulk modulus,pressure derivative of bulk modulus,second-order elastic constants,Zener anisotropy factor,Poisson s ratio,Young s modulus,and isotropic shear modulus.In order to gain further information,the pressure-and temperature-dependent behaviour of the volume,bulk modulus,thermal expansion coefficient,heat capacity,entropy,Debye temperature and Gru¨neisen parameter were also evaluated over a pressure range of 0-20 GPa for Al 2 Sc and 0-17 GPa for Al 2 Y compound and a wide temperature range of 0-2000 K for both compounds.The obtained results were compared with the other reported values.
Yasemin ztekin iftci1，Kemal olakoglu1
1. Department of Physics,Gazi University
摘 要：To understand deeply the structural,elastic and thermodynamic characteristics of Al 2 X （X= Sc,Y） compounds in C15 type （space number 227） Cu 2 Mg structure,we have performed ab-initio density functional theory within the local density approximation （LDA） and the generalized gradient approximation （GGA）.The thermodynamic properties of the considered structures are obtained through the quasi-harmonic Debye model.We have presented the results on the basic physical parameters,such as the lattice constant,bulk modulus,pressure derivative of bulk modulus,second-order elastic constants,Zener anisotropy factor,Poisson s ratio,Young s modulus,and isotropic shear modulus.In order to gain further information,the pressure-and temperature-dependent behaviour of the volume,bulk modulus,thermal expansion coefficient,heat capacity,entropy,Debye temperature and Gru¨neisen parameter were also evaluated over a pressure range of 0-20 GPa for Al 2 Sc and 0-17 GPa for Al 2 Y compound and a wide temperature range of 0-2000 K for both compounds.The obtained results were compared with the other reported values.
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