Generalized Slater-Pauling rule for the inverse Heusler compounds

We present extensive first-principles calculations on the inverse full-Heusler compounds having the chemical formula X₂YZ, where X=Sc, Ti, V, Cr, or Mn; Z=Al, Si, or As; and the Y ranges from Ti to Zn. Several of these compounds are identified to be half-metallic magnets. We show that the appearance of half-metallicity is associated in all cases with a Slater-Pauling behavior of the total spin-magnetic moment. There are three different variants of this rule for the inverse Heusler compounds depending on the chemical type of the constituent transition-metal atoms. Simple arguments regarding the hybridization of the d orbitals of neighboring atoms can explain these rules. We expect our results to trigger further experimental interest in these types of half-metallic Heusler compounds.