The effect of Lanthanide doping on the structural, elastic, thermodynamic and electronic properties of YBi: An ab-initio study

The main investigation goal of this work is to give report on the effect of Lanthanide doping in YBi. The present results were done by means of DFT calculations. The analysis of structural calculations reveals that, the lattice parameters of LaxY1-xBi varies linearly with the investigated concentration x, which indicates that the Vegard's law is valid for this calculation showever, for the effect on bulk modulus the results show the existing of a large deviation from a linear concentration dependence (LCD). The elastic constants Cij and their related macroscopic moduli was predicted. The influence of La-doped on thermodynamic stability was explored on the basis of regular solution model. Furthermore, the temperature effect on: heat capacity at constant volume (CV), thermal expansion (α) and Debye temperature (θD) have been investigated by the quasi-harmonic Debye model. To calculate the electronic structure of the investigated compounds we have used the Tran and Blaha-modified Becke-Johnson (TB-mBJ) method. The electronic structures reveal that the compounds with the concentration 0, 0.25 and 0.5 have semi metallic characters. Furthermore, the results reveal a gapless semiconducting behavior for La0.75Y0.25Bi alloy.