Unified Explanation Of Chemical Ordering, The Slater-Pauling Rule, And Half-Metallicity In Full Heusler Compounds

In the present work we developed an orbital coupling model for cubic full Heusler compounds that provides a unified set of rules that account for the chemical ordering, magnetic moment, and composition of the most promising candidates for half-metallicity. The origin and limitations of the rules are clearly described. To the best of our knowledge all of the several dozen half-metallic Heusler compounds known in the literature that follow the M-t = N-t - 24 or M-t = N-t - 28 generalized Slater-Pauling behavior satisfy the derived half-metallicity rule. Calculations performed by using density functional theory-performed for 259 compounds-confirm the validity of our model and derived rules for broad classes of Heusler compounds.