Electronic structure, magnetic, and thermoelectric properties of BaMn2As2 compound: a first-principles study

We report the magnetic stability, antiferromagnetic ordering, electronic, magnetic, and thermoelectric properties of BaMn2As2 employing the full-potential linearized augmented-plane wave method under the framework of density functional theory. The exchange-correlation energy was treated using the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) and GGA plus Hubbard U parameter method. From structural relaxation, we reveal that antiferromagnetic (A-AFM) state is more appropriate for BaMn2As2 than other known configurations. Under electronic properties, BaMn2As2 shows metallic nature in paramagnetic (PM) and antiferromagnetic phase (AFM). Further, the decrease in electrical conductivity over the entire temperature range characterize the metallic nature of BaMn2As2. The electronic band structure calculation demonstrates that Mn-3d and As-4p orbital hybridization are essential for the band gap formation, suggesting BaMn2As2 , a hybridization-gap semiconductor. The total magnetic moment of BaMn2As2 in ferromagnetic phase is -9.54 mu B, with a major contribution from Mn atom. In thermoelectric, we obtain a negative Seebeck coefficient (S), n-type electrical conductivity, and a maximum ZT value of 0.40. Our study suggests BaMn2As2 as a novel candidate for spintronics and waste heat management.