Transição metal-isolante em fulleritos dopados com metais alcalinos

José Carlos Cechin, Ronaldo Mota


In the present article of the metallic or insulating characters of alkali doped is studied. In particular, the ocurrence of a metalic phase in potassium doped systems and its nonocurrence in sodium doped systems are analysed through the Gutzwiller approximation on a deqenerate Hubbard model. Using interaction and bandwidth parameters derived from INDO-CI calculations in the molecular cluster approach, as presented earlier by Coutinho, Canuto, Mota and Fazzio, the nonmetal-metal transitions are discussed in the systems. From the obtained results for the relation between the derived parameters and doping concentrations, it is possible to help to elucidate the diverse behaviours presented by fullerides doped with potassium and sodium.


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