Theoretical investigation of the mechanical and thermodynamics properties of the noncentrosymmetric superconductor SrAuSi3.

The lattice parameters, electronic structures, elastic constants, Vicker's hardness and thermodynamics properties of SrAuSi 3 were systematically investigated by using first-principles and the quasi-harmonic Debye model. The calculated lattice parameters are in excellent agreement with the experimental data. The calculated elastic constants C ij reveal that SrAuSi 3 is mechanically stable but anisotropic. The elastic anisotropy is further illustrated by the three-dimensional (3D) of bulk modulus and Young's modulus. The polycrystalline elastic modulus: shear modulus, Young's modulus, Poisson's ratio are derived from the obtained single-crystal elastic constants. In addition, the temperature dependence of the expansion coefficient, specific heat and Debye temperature are investigated through the quasiharmonic Debye model. Finally, Using the McMillan formula the T c ∼ 9.94 K, which is conflicts with the experimental data (1.54 K). Presumably, the T c suppression phenomenon due to the presence of an antisymmetric spin–orbit coupling (ASOC) as a consequence of the lack of inversion symmetry. [ABSTRACT FROM AUTHOR]