Magnetic properties of (Co, Ni, Mn)3O4 spinels
[EN] Magnetic properties of new materials, based on the general formula CoxNiyMnzO4 (x+y+z= 3), have been investigated as a function of magnetic field and temperature. The behavior observed in the paramagnetic regime (220 K ≤ T ≤ 400 K) shows a direct correlation with the nominal cation concentratio...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2004 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/4443 |
| Acceso en línea: | http://hdl.handle.net/10261/4443 |
| Access Level: | acceso abierto |
| Palabra clave: | Magnetic oxides Spinels Magnetic exchange Ferrimagnetic properties Óxidos magnéticos Espinelas Interacciones de intercambio Ferrimagnetismo |
| Sumario: | [EN] Magnetic properties of new materials, based on the general formula CoxNiyMnzO4 (x+y+z= 3), have been investigated as a function of magnetic field and temperature. The behavior observed in the paramagnetic regime (220 K ≤ T ≤ 400 K) shows a direct correlation with the nominal cation concentration. The paramagnetic-ferrimagnetic transition which takes place at T = Tc depends on the overall composition, going from Tc = 120 K (for Co0.2NiMn1.8O4) up to Tc = 210 K (for Co1.2Ni0.3Mn1.5O4). A second transition is observed at lower temperatures, corresponding to a second ordered magnetic sublattice. This second transition takes place at about 60 K (for Co0.6NiMn1.4O4), increasing with the cobalt content up to about 160 K. Under an external magnetic field, both transitions merge into a single one, with a characteristic temperature Tmax, which rapidly decreases with increasing field. Magnetization loops M(H) obtained at 5 K show a typical behavior of soft magnetic materials, with low coercive fields. Low conductivity values were observed at room‑temperature, increasing by a factor of 200-1000 at high temperatures (400 C), which make these compounds to be very interesting materials for potential applications as NTCR thermistors. |
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