Layered transition-metal pnictide SrMnBi2with metallic blocking layer

Abstract

The physical properties and the band structure of the layered pnictide SrMnBi${}_{2}$ were investigated. This compound has a crystal structure similar to that of the superconducting Fe pnictides, and is a bad metal with large residual resistivity. Magnetic order sets in at very high temperatures, around 290 K, as shown by magnetization, resistivity, and specific heat data. Band structure calculations using density functional theory (DFT) are consistent with the thermodynamic and transport measurements, suggesting a checkerboard antiferromagnetic (cAFM) ground state and a localized picture for the magnetism. Moreover, DFT results indicate that the Mn 3$d$ electrons are strongly correlated, and that, unlike in the known superconductors, the Sr-Bi${}_{(1)}$ layer is metallic. One more notable feature of the DFT calculation is the multiple Dirac-cone-like dispersion close to the Fermi level.