Search for Half-Metallic Compounds in Co₂MnZ (Z=IIIb, IVb, Vb Element)

Electronic structures of Heusler alloys Co 2 MnZ (Z=sp elements) were calculated to search half-metallic compounds. In this paper, it will be shown that stoichiometric compounds Co 2 MnZ are half-metallic when Z is Si and Ge. Considering the effect of Z atom on the band structure, we can predict that there are half-metallic compounds in nonstoichiometric compounds Co 2 MnZ 1- x Z x ' and that the position of the Fermi level is adjustable in the energy gap of the minority-spin state by changing the composition x .