Electronic, Optical, and Thermoelectric Properties of BaFe۲-xZnxAs۲(x=۰,۱,۲)orthorhombic Polymorphs: DFT Study

Based on the calculations of density functional theoryand Generalized Gradient approximation (GGA),mechanical, electronic, optical and thermoelectricproperti BaFe۲-xZnxAs۲ (x=۰,۱,۲) have been investigatedin orthorhombic phase. For all three BaFe۲-xZnxAs۲(x=۰,۱,۲), the energy curves have an equilibrium point interms of their volume. For x=۱ and x=۲, the bonds takeon an ionic shape. Electronic calculations show that byapplying the modified Becke-Johonsom (mBJ)approximation, the x=۲ compound is converted to a ptypesemiconductor with a gap of ۰.۱۱ eV. However,magnetic behavior can be seen for the other twoimpurities. At x=۲, the band structure illustrates a directgap. Optical diagrams display that the parts of thedielectric function exhibit strong metallic behavior forimpurities x=۰, ۱, and also an optical gap can be detected.Moreover, the Seebeck coefficient provides that a goodstability is observed in its behavior at room temperatureonwards to reach the saturation limit of ۲۰۰ μvK-۱.Additionally, the figure of merit reaches a saturation limitin the range of ۰.۶ to ۰.۷ at this temperature range.

Keywords:

BaZn۲As۲ , DFT , Thermoelectric properties