Electronic structure study of the dependence of the pseudogap on the icosahedral cluster size and glue atoms

Abstract

Electronic structures of crystalline Al_l2Mn, Al₄₂Mn₁₃ and Al₅₄Mn₁₃ are calculated by the tight-binding linear muffin-tin orbital method with the atomic sphere approximation in the local density functional framework. The density of states for Al₁₂, Mn shows a pseudogap at the Fermi level, whereas it is very much reduced and away from Fermi level in the case of the Al₄₂Mn_l3 crystal. The evolution of a pseudogap near the Fermi level is observed in A1₅₄Mn₁₃ with the addition of glue atoms. Our results show that the pseudogap does not depend upon the icosahedral cluster size, for the Al-Mn system; however, it is sensitive to the presence of the glue atoms.