Chemical Substitution Induced Half-Metallicity in Heusler Alloys

Half-metals are a class of materials that combine properties of electric conductors and insulators. Here we study CrMnSb0.5Si0.5. It is shown that the parent Heusler compound — a compound which consists of two transition metals and an element from the p-block — CrMnSb is not half-metallic in its ground state; however, it undergoes a half-metallic transition under a uniform compression of ~1.5%, which is something achievable in practice. We demonstrate a thermodynamic stability of this compound, its half-metallic electronic structure, and ferrimagnetic alignment. At the same time, it is shown that in thin-film geometry the spin-polarization of this material is reduced due to the emergence of surface states in the minority-spin energy gap. This research is supported by the National Science Foundation (NSF) under Grant Numbers 2003828 and 2003856 via DMR and EPSCoR