Effect of GGA on the half-metallicity of the itinerant ferromagnet CoS2 - art. no. 180401

The half-metallicity of CoS2, important for its possible use in spintronic applications. is investigated by means of density functional full-potential linearized augmented plane wave calculations within both the local spin-de nsity approximation (LSDA) and the generalized gradient approximation (GGA) . In contrast with earlier and our own predictions employing the LSDA, we f ind that CoS2 is clearly half-metallic with use of the GGA for the exchange -correlation functional. While the GGA induced modifications of the band st ructure are significant, they are limited to only the e(g down arrow) state which is responsible for producing the half-metallicity, while leaving all other features the same as those obtained by LSDA. We address the recently measured reflectivity spectra and rectify the assignments given for their underlying optical transitions.