Electronic, elastic and thermal properties of SrCu2As2 via first principles calculation

Abstract

ThCr2Si2-type crystal has a large family member, most of which have certain unusual properties. In this work, the electronic, elastic and thermal properties of the recently re-synthesized SrCu2As2 are investigated by employing first principles calculation. The characters of the band structure and the partial density of states (PDOS) of SrCu2As2 are analyzed, which shows that SrCu2As2 is a metallic crystal with no magnetism. The calculated elastic constants reveal that SrCu2As2 is mechanically stable but anisotropic; the anisotropy is further illustrated by the direction-dependent linear compressibility and Young’s modulus. By analyzing, we find that the corresponding shear deformation is most easy to take place when the shear stresses are imposed on the vertical {100} planes along the horizontal 〈100〉 directions. Besides these, other elasticity-relevant properties, including the bulk modulus, shear modulus, the Poisson ratio, the velocities of acoustic waves and the Debye temperature, are also derived. The specific heat CV and CP as functions of temperature (T) are obtained from quasi-harmonic Debye model, the curve of Cp–T consists well with the experimental data. Meanwhile, the thermal expansion coefficient α is also predicted.