| Numéro |
J. Phys. IV France
Volume 07, Numéro C1, Mars 1997
7th INTERNATIONAL CONFERENCE ON FERRITES
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|---|---|---|
| Page(s) | C1-525 - C1-526 | |
| DOI | https://doi.org/10.1051/jp4:19971214 | |
J. Phys. IV France 07 (1997) C1-525-C1-526
DOI: 10.1051/jp4:19971214
Cationic Distribution in Defect Co-Mn Ferrites from Neutron Diffraction
E. Elbadraoui1, J.L. Baudour1, F. Bouree2, Ph. Tailhades3 and A. Rousset31 Laboratoire Matériaux Multiphasés et Interfaces, E.A. 1357, Université de Toulon, BP. 132, 83957 La Garde cedex, France
2 Laboratoire Léon Brillouin, CEN Saclay, 91191 Gif sur Yvette cedex, France
3 LCMI, URA 1311 du CNRS, UPS, 118 route de Narbonne, 31062 Toulouse cedex, France
Abstract
Submicron stoichiometric cobalt manganese ferrites oxidized in air, at low temperature (<500°C) give defect spinel ferrites which exhibit a substantial increase in coercivity, reaching a maximum for ferrites oxidized near 350°C and slowly cooled (5°C/min) from the oxidation temperature. Two [MATH] samples oxidized at 350°C but exhibiting notably different coercivities because of different cooling rates (Hc=1750 Oe after quenching ; Hc=2350 Oe after slow cooling) have been analyzed by neutron diffraction at T=6K. They exhibit almost exactly the same structural and magnetic parameters, indicating that the difference between the coercivities has a purely local origin. Similar cationic distributions have been inferred. Neutron diffraction reveals a classical collinear ferrimagnetism on the A and B sublattices of the spinel structure.
© EDP Sciences 1997