The stable CaBe2Ge2 structures in antimonide compounds ATM2Sb2 (A = Ca, Sr, Ba; TM = Fe, Co, Ni, Cu): A first-principles study

We have investigated the structural properties of 3d transition metal antimonide compounds ATM2Sb2 by first-principles calculations. We find that the calcium-based CaNi2Sb2, the strontium-based SrNi2Sb2, SrCu2Sb2, and the barium-based BaCu2Sb2 are stable in the CaBe2Ge2-type structure. All the other compounds are stable in the ThCr2Si2-type structure. SrCo2Sb2 in the ThCr2Si2-type structure has specifically ferromagnetic preference. The stable compounds in the CaBe2Ge2-type structure have strong interlayer interactions. Although the stable stacking structures are different, all the Fe-based compounds have the stripe-like antiferromagnetic ground states. The Co-based compounds have the ferromagnetic ground states. The Ni-based and Cu-based compounds have the nonmagnetic ground states.

► ATM2Sb2 crystallize in different stable structures.
► Fe-based compounds are antiferromagnetic.
► Co-based compounds are ferromagnetic.