Ab initio study of the thermodynamic properties of rare-earth-magnesium intermetallics MgRE (RE = Y, Dy, Pr, Tb)

作者：Wang Rui^*; Wang Shaofeng; Wu Xiaozhi

来源：Physica Scripta, 2011, 83(6): 065707.

DOI：10.1088/0031-8949/83/06/065707

We have performed an ab initio study of the thermodynamical properties of rare-earth-magnesium intermetallic compounds MgRE (RE = Y, Dy, Pr, Tb) with B2-type structures. The calculations were carried out in the framework of density functional theory and density functional perturbation theory in combination with the quasiharmonic approximation. The phonon-dispersion curves and phonon total and partial density of states have been investigated. Our results show that the contribution of RE atoms is dominant in phonon frequency, and this character agrees with the previous discussion by using atomistic simulations. The temperature dependence of various quantities such as thermal expansion, bulk modulus and heat capacity is obtained. Electronic contributions to the specific heat are discussed, and are found to be important for the calculated MgRE intermetallics.

• 出版日期2011-6
• 单位重庆大学