Nonlinear elastic properties of superconducting antiperovskites MNNi 3 (M =Zn, Cd, Mg, Al, Ga, and In) from first principles
KAUST DepartmentPhysical Science and Engineering (PSE) Division
Online Publication Date2014-05-22
Print Publication Date2014-08
Permanent link to this recordhttp://hdl.handle.net/10754/563556
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AbstractWe present theoretical studies for the third-order elastic constants (TOECs) of superconducting antiperovskites MNNi 3 (M = Zn, Cd, Mg, Al, Ga, and In) using the density functional theory (DFT) and homogeneous deformation method. From the nonlinear least-square fitting, the elastic constants are extracted from a polynomial fit to the calculated strain-energy data. Calculated second-order elastic constants (SOECs) are compared with the previous theoretical calculations, and a very good agreement was found. The nonlinear effects often play an important role when the finite strains are larger than approximately 2.5 %. Besides, we have computed the pressure derivatives of SOECs and provided rough estimations for the Grüneisen constants of long-wavelength acoustic modes by using the calculated TOECs. © 2014 Springer Science+Business Media New York.
SponsorsThe work is supported by the Natural Science Foundation of China (11104361), State Key Laboratory of Coal Mine Disaster Dynamics and Control in Chongqing University(2011DA105287FW201210) and the Fundamental Research Funds for the Central Universities (CDJZR14328801).