First-principles Study on Half-metallicity and Magnetism for Zinc-blende CrS(001) Surface

We investigated the half-metallicity and magnetism for the zinc-blende CrS(001) surfaces by use of the full-potential linearized augmented plane wave (FLAPW) method. We considered two-types of (001) surfaces terminated by Cr (Cr-Term) and S (S-Term) atoms, respectively. From the calculated layer-by-layer density of states, it is found that both of the systems retain the half-metallicity at the (001) surfaces. The calculated magnetic moment (4.07 mu(B)) for the CrS(S) atom in Cr-Term is enhanced considerably compared to the bulk value (3.61 mu(B)) while that (3.15 mu(B)) of the Cr(S-1) in S-Term is much reduced.