Physical properties of Mn- and Fe-doped CaS: A DFT insights

In the present paper, we investigate the structural, electronic magnetic and elastic properties of ordered dilute ferromagnetic semiconductors Ca0.75Mn0.25S and Ca0.75Fe0.25S using the full-potential linearized augmented plane-wave (FP-LAPW) method. We adopt the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA), GGA-PBE + U and the modified Becke-Johnson exchange potential for the exchange-correlation energy and potential. The spin-polarized electronic band structures and density of states of Ca0.75Fe0.25S calculated by GGA-PBE, mBJ-GGA-PBE and GGA-PBE + U show that the minority spin channel has metallic nature and the majority spin channel has a half-metallic gap of 0.74,0.78 and 0.54 eV, respectively. For Ca0.75Mn0.25S the band structures calculated within GGA-PBE and mBJ-GGA-PBE shows a half-metallic behavior, whereas when we use the GGA-PBE + U, we see that this compound is semiconductor with magnetic moment of 5 mB per formula unit. Moreover, the elastic constants, bulk modulus, shear modulus, and universal elastic anisotropy are calculated, which have not been measured yet. Analysis of elastic constants demonstrated that both Ca0.75Mn0.25S and Ca0.75Fe0.25S are mechanically stable. (C) 2021 Elsevier B.V. All rights reserved.