First-Principles Studies of Structural, Electronic and Magnetic Properties of the CrS, CrSe and CrTe Compounds

Using first-principles calculation within the generalized gradient approximation (GGA) and GGA + U (Hubbard Coulomb onsite correction), we investigated the structural, electronic and magnetic properties of CrS, CrSe and CrTe compounds in different phases. We found that the NaCl phase is the lowest energy structure in comparison to the other investigated phases within the GGA + U approach for CrS, CrSe and CrTe compounds. The CrX compounds investigated in the NaCl phase are all half-metallic ferromagnets with a net magnetic moment of 4.0 mu(B) within the GGA + U approximation. From the density of states profile and charge density distribution, the observed half-metallic ferromagnetism in the CrS, CrSe and CrTe compounds is due to the spin polarized 3d orbitals of the Cr atoms. The observed stable half-metallic ferromagnetism in the NaCl phase of the CrS, CrSe and CrTe compounds should motivate further experimental studies on the possible application of these compounds as spintronic materials.