engleski

Inverse spinel structure in cobalt doped gahnite

Powder ZnAl2O4 (gahnite) samples doped with 0-100 at% Co were obtained by a sol-gel technique. X-ray powder diffraction was used to characterize the samples. Gahnite samples were cubic with spinel-type structure, space group Fd-3m. Cobalt doping caused the nonuniform increase of unit-cell parameter. The structure of gahnite samples was refined by the Rietveld method. Location of Co2+ was performed by the EPR spectroscopy. Cobalt doping of gahnite induced the inverse spinel structure already for 4 at% Co, inversion parameter increased with Co2+ doping level. Metal-oxide distances in the (Al, Co)O6 octahedra dominantly influenced the unit-cell parameter of Co-doped gahnite.

gahnite; spinel structure; X-ray powder diffraction; Rietveld method

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