Estudo por EXAFS de nanoparticulas de cobalto imersas em uma matriz de cobre

AUTOR(ES)

Julio Criginski Cezar

DATA DE PUBLICAÇÃO

1998

RESUMO

Granular solids are a class of materia1s that presents several properties, with significant possibilities in the technological applications. In this work we have performed structural characterization of a granular solid of cobalt in a copper matrix, fabricated by melt-spinning method and thermally treated by Joule heating. In principle, the thermal treatment allows the coalescence of cobalt atoms, forming cobalt particles in the copper matrix. This material had attracted the magnetism community interest, due the fact that it presents the giant magnetoresistance (GMR) effect, comparable to the metallic multilayers. The structural characterization had been done using the EXAFS (Extended X ray Absorption Fine Structure) technique, which gives short range information around a specific atomic element. We have obtained the first neighbour coordination number and the first neighbour average distance. The first neighbour distance displayed a dependence on the thermal treatment, and using a very simple model, we have9+ associated this dependence with the cobalt particle size

ASSUNTO(S)

magnetoresistencia nanoparticulas

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