FIRST-PRINCIPLES STUDY ON THE MRh12 (M = Rh, Fe, Co, AND Ni) CLUSTERS
X. Kuang1, X. Wang2, G. Liu2
1 College of Mathematics and Physics Chongqing University School of Science, Southwest University of Science and Technology
2 College of Mathematics and Physics Chongqing University
xkdkxj@yahoo.com.cn
Ключевые слова: MRh12 cluster, geometrical structure, electronic and magnetic properties
Страницы: 696-703
Аннотация
In this paper, a first-principles study on the stability, electronic and magnetic properties of MRh12 (M = Rh, Fe, Co and Ni) clusters is performed. By optimizing the geometrical structure, we find that MRh12 clusters change from a perfect icosahedron to a distorted structure and have an obvious bond length contraction as compared with the corresponding bulk phase; FeRh12, CoRh12, and NiRh12 clusters are more energetically stable than the RhRh12 cluster. The effect of the impurity M on the density of states, valence band width, HOMO and LUMO for MRh12 clusters is not significant, but when the central Rh atom is substituted with M, the magnetic moment of MRh12 reduces dramatically. The Mulliken population analysis indicates that there are more charge transfers from other orbitals to Rh4d and M3d orbitals, and the spd hybrid effect in d orbitals of MRh12 clusters is stronger than that in the RhRh12 cluster. this situation means that the unpaired d electrons have more chance to be paired, and the magnetic moments of MRh12 clusters can be reduced reasonably.
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