Revisited Compensated Half-Metallicity in Inverse-Heusler Compounds Cr$_2$CoZ (Z=Al, Ga, In).

Using three correlated band approaches, namely the conventional band approach plus on-site Coulomb repulsion $U$, the modified Becke-Johnson functional, and hybrid functional, we revisited a few of the Cr-based inverse-Heusler compounds that are known to manifest a low-moment ferrimagnetic character, in the hope of finding promising candidates for compensated half-metals (CHMs). These approaches commonly indicate that Cr$_2$CoAl, which was synthesized recently and showed a high Curie temperature, is a precise CHM, while Cr$_2$CoGa and Cr$_2$CoIn are ferrimagnets with a small moment. This is further confirmed by the fixed spin moment approach. Changing the volume of Cr$_2$CoAl by $\pm$ 5% does not alter the CHM state, suggesting that this state is robust even under application of pressure. Our findings are expected to pave the way for realization of room temperature CHMs.