J. Phys. IV France 07 (1997) C1-517-C1-518
Microstructural Characterization of Gamma Ferric Oxides of Different GenesisG.N. Kryukova and S.V. Tsybulya
Institute of Catalysis of SB RAS, pr. Lavrentieva 5, Novosibirsk 630090 Russia
Using X-ray powder diffraction and high resolution electron microscopy the peculiarities of the structural arrangement of γ-ferric oxide microcrystals prepared with the thermal treatment of acircular magnetite and plasmochemistry were studied. Both samples were found to have a complete structural equivalence : distortion of the basic spinel-like unit cell is not observed, whereas ordered distribution of the cation vacancies on the octahedral positions results in the formation of the tetragonal superlattice. Different magnetic properties of the materials in question seem to be associated with their microstructural features, i.e. the orientation of the multiple twin domains of those every particles of both samples are composed with respect to the developed planes of oxide microcrystals.
© EDP Sciences 1997