| Автор | Viart, N. |
| Автор | Pourroy, G. |
| Автор | Grenèche, J.-M. |
| Автор | Niznansky, D. |
| Автор | Hommet, J. |
| Дата выпуска | 2000 |
| dc.description | Composites made of iron and Cr doped magnetite are obtained by precipitation from the metallic chlorides salts into a KOH solution heated under reflux. A KOH concentration of 14 mol l<sup>−1</sup> is required. The composition of the samples is determined by X-ray diffraction, TG measurements, chemical analysis and Mössbauer spectrometry. The higher the chromium content, the smaller the lattice parameter and the lower the metal ratio. For Cr/Fe ≤ 0.1, the chemical formula of the composites can be written Fe<sub>A</sub>/(Fe$^{\nu+}_{x}$Cr$^{3+}_{y}\square_{3-(x+y)}$O$_{4})_{1-{\rm A}}$, $0\le y\le0.23$. We show that only in-field Mössbauer spectrometry at low temperature is suitable to estimate unambiguously both the proportions of octahedral and tetrahedral iron sites in spinel and the valence of delocalised iron state, if any. A peculiar A-site occupation by either vacancies or Cr<sup>3+</sup> ions is observed. This is probably due to the low temperature synthesis. The two phases, metal and spinel are found to be intimately mixed within the nanometer sized particles. For Cr/Fe ratios higher than 0.1, hydroxide phase is also present. |
| Формат | application.pdf |
| Издатель | EDP Sciences |
| Копирайт | © EDP Sciences, 2000 |
| Название | Microstructural and magnetic properties of Fe/Cr-substituted ferrite composites |
| Тип | research-article |
| DOI | 10.1051/epjap:2000169 |
| Electronic ISSN | 1286-0050 |
| Print ISSN | 1286-0042 |
| Журнал | The European Physical Journal Applied Physics |
| Том | 12 |
| Первая страница | 37 |
| Последняя страница | 46 |
| Аффилиация | Viart N.; Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe des Matériaux Inorganiques (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France |
| Аффилиация | Pourroy G.; Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe des Matériaux Inorganiques (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France |
| Аффилиация | Grenèche J.-M.; Laboratoire de Physique de l'État Condensé (UPRESA 6087), Université du Maine, avenue O. Messiaen, BP 535, 72085 Le Mans Cedex 9, France |
| Аффилиация | Niznansky D.; Institute of Inorganic Chemistry AS CR, Rez near Prague, Czech Republic |
| Аффилиация | Hommet J.; Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe Surfaces Interfaces (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France |
| Выпуск | 1 |
