First-principles study of the magnetic and electronic properties of ACr2As2 (A = Sr, Ba)

Abstract We report a detailed density functional theory investigation for ACr2As2 (A = Sr, Ba), which are isostructural to their iron counterparts AFe2As2, parent compounds of iron-based superconductors. The calculated results for these two compounds are quite similar, indicating that the A site ions have only a relatively small impact on the magnetic and electronic structures. It is found that both ACr2As2 favor an itinerant antiferromagnetic ground state with G-type spin arrangement, and possess a sizable magnetocrystalline anisotropy energy with the easy axis directed along the c axis perpendicular to the CrAs plane. Furthermore, the optimized lattice constants and internal atomic parameter of ACr2As2 are found to be sensitive to magnetic ordering, which implies the presence of a magnetostructural coupling effect.