Electronic structures and crystal field splitting of antiperovskite XNMn3 (X = 3d and 4d elements)

Abstract

Antiperovskites have diverse novel physical properties and potential applications in fields of superconducting techniques, magneto-electronic devices, etc. Nevertheless, their fundamental electronic structures, such as ground state magnetic configurations and crystal field splitting, are still not yet fully understood. We thus utilize first principles calculations combining on-site Coulomb interaction of the Mn-3d orbitals to investigate the electronic and magnetic properties of the XNMn3 (X=Ni, Cu, Zn, Ga, As, Rh, Pd, Ag, In, Sn, Sb). Our results show that the Mn atoms prefer to align antiferromagnetic configuration in the ground state. Two nonequivalent Mn atoms (NEMAS) are identified in Mn6N octahedral unit. The Mn-3d orbitals with longer Mn-N bond length in the octahedron split into one doublet and three singlets, and the 3d orbitals of other Mn atoms with shorter Mn-N bond length split in five singlets, i.e. the degeneracy is completely relieved. These findings certainly offer an insight into clarifying the magnetic and electronic properties of these antipervoskites.