Electronic structure, mechanical and thermoelectric properties of the full Heusler Ba 2 AgZ (Z = Bi, Sb) alloys: insights from DFT study

We have carried out a theoretical calculation based on density functional theory using full-potential linearized augmented plane-wave method implemented within the wien2k program to investigate the structural, electronic, elastic, thermodynamic and thermoelectric properties of full Heusler alloys Ba2AgZ (Z = Bi, Sb). The exchange and correlation potential are treated by different approximations: LDA, GGA-PBE and mBJ-GGA. The electronic band structures of both alloys show them as narrow indirect band gap semiconductor. Moreover, these compounds are characterized by a high value of the figure of merit (ZT) (close to the unity) and Seebeck coefficient (S) which makes them promising candidates for thermoelectric applications. Thermal properties, including the heat capacity Cv, the entropy S and the Debye temperature ( $$ \theta_{\text{D}} $$ ), have been successfully computed using the quasi-harmonic Debye model. The mechanical properties reveal that the studied compounds are mechanically stable and can be synthesized experimentally. It is noteworthy that the present calculation is a first quantitative theoretical prediction of the electronic, elastic, thermodynamic and thermoelectric properties of these compounds. We believe that the present study will be useful for experimentalists for experimental synthesis of these compounds in future.