Design of half-metallic antiferromagnets: transition metal chalcogenides and pnictides

Half-metallic antiferromagnts are the materials that exhibit half-metallicity and antifirromagnetism (compensated ferrimagnetism) simultaneously. Such materials are especially useful for spintronics devices since they have 100 \% spin-polarized Fermi surfaces despite of their robustness against a disturbance of external magnetic field. We found that (XY)Z$_2$, where X and Y are transition metal elements and Z is a chalcogens or a pnictigen, show half-metallic antiferromagnetism when the sum of effective d electron numbers of X and Y is 10. Examples are (CrFe)S$_2$ and (CrFe)Se$_2$. We report a systematic investigation of the electronic structure and transport properties of these materials calculated by the KKR-Green's function method combined with the Kubo-Greenwood formula.