Theoretical investigation of the elastic and structural properties of theLaLi۳Sb۳ compound by the pseudo-potential method

In this research, the structural and elastic constant properties of the LaLi۳Sb۳ compound, witha trigonal crystal structure (space group p۳۱m) have been discussed [۱]. The calculations havebeen done in the framework of the density functional theory and with the pseudo-potential methodin the generalized gradient approximation (gga) by the quantum espresso software [۲], and further,the elastic constants were investigated based on the density functional theory. Elastic constantsgive information about the hardness, stability, ductility, and brittleness of compounds. Moreover,obtaining the elastic constants subsequently gives information about elastic properties such asvolume modulus B, shear modulus G, Young's modulus, and Poisson's ratio. Therefore, studyingelastic constants is a functional and fundamental tool to understand the physical, chemical, andmechanical properties of the structure and can be used as a measure criterion of the resistance of acrystal to an externally applied stress. The amounts of bulk modulus B = )[۴۰.۸]( G, Young'smodulus = ([۸۰.۷]) GPa and shear modulus = ([۳۴.۵]) GPa have been obtained. The value ofPoisson's ratio ν=([۰.۱۷]) has been obtained for this crystal structure, which indicates the existenceof a covalent bond between the two atoms. The Poisson's ratio is in the range of [(۰. ۱-۰.۲۵)]among solids implies the presence of a covalent bond [۳]. The structure of this compound showsa small and indirect band gap between L and Γ, and also the examination of the partial density ofstates determined that the maximum contribution of the conduction band is related to the d orbitalof the La atom and in the valence band is related to the p orbital of the Sb atom and the d orbitalof the La atom. In this work, the elastic properties of this compound have been investigated for thefirst time

کلیدواژه ها:

Band structure ، LaLi۳Sb۲ ، DFT ، Elastic calculations