$d^0$-$d$ half-Heusler alloys: New class of stable spintronic materials

It is shown by rigorous ab initio calculations that half-Heusler alloys of transition metals and $d^0$ metals, defined by the valence electronic configuration $ns^{1,2},(n-1)d^0$, can produce all kinds of half-metallic behavior including the elusive Dirac half-semimetallicity that is reported for the first time in the real 3D material CoKSb. Together with the predicted magnetic and chemical stability, this paves the way for massless and dissipationless spintronics of the future. Furthermore, the introduction of $d^0$ atoms is shown to stabilize the otherwise instable chemical structure of zinc-blende transition metal pnictides and chalcogeneides without altering the $p$-$d$ exchange that is mainly responsible for their half-metallicity, therefore, making their application in spintronic devices feasible.