A prediction of half-metallicity in a Co2-based full Heusler compound with the 4d transition-metal element, Co2ZrSi:: A first-principles study

We Calculated the electronic structures of several Co-2-based full Heusler compounds with 4d transition elements T and Si, Co-2 TSi (T = Y, Zr and Nb), by using the all electron full potential band method and found that the Co2ZrSi is half-metallic ferromagnet. The calculated atomic resolved density of states (DOSs) for Co2ZrSi showed that it had a considerably large minority spin gap (0.94 eV) and that the Fermi level was pinned just at the middle of the gap. The fact that the Co2ZrSi had an integer value for the magnetic moment, 2.000 mu(B) per formula unit (f.u.), also indicated that this compound was half-metallic. Calculations for the compounds Co2YSi and Co2NbSi showed that they were not half-metals, but ferromagneic metals with magnetic moments of 1.002 and 2.243 mu(B)/f.u., respectively. The Fermi level of Co2YSi, located at the left edge of the minority spin gap, made the material nearly half-metallic while that Of Co2NbSi was positioned just below a large peak of minority Co 3d states.