Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-06-22T22:50:33.378Z Has data issue: false hasContentIssue false
  • English
  • Français

Microstructural and magnetic properties of Fe/Cr-substituted ferrite composites

Published online by Cambridge University Press:  15 October 2000

N. Viart ,
G. Pourroy ,
J.-M. Grenèche ,
D. Niznansky  and
J. Hommet
N. Viart*
Affiliation:
Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe des Matériaux Inorganiques (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France
G. Pourroy
Affiliation:
Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe des Matériaux Inorganiques (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France
J.-M. Grenèche
Affiliation:
Laboratoire de Physique de l'État Condensé (UPRESA 6087), Université du Maine, avenue O. Messiaen, BP 535, 72085 Le Mans Cedex 9, France
D. Niznansky
Affiliation:
Institute of Inorganic Chemistry AS CR, Rez near Prague, Czech Republic
J. Hommet
Affiliation:
Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe Surfaces Interfaces (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France
*
viart@ipcms.u-strasbg.fr
Get access

Abstract

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−1 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 FeA/(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 Cr3+ 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.

Keywords

Type
Research Article
Information
The European Physical Journal - Applied Physics , Volume 12 , Issue 1 , October 2000 , pp. 37 - 46
Copyright
© EDP Sciences, 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Carles, V., Laurent, C., Brieu, M., Rousset, A., J. Mater. Chem. 9, 1003 (1999). CrossRef
Hwang, H.J., Toriyama, M., Sekino, T., Niihara, K., J. Eur. Ceram. Soc. 18, 2193 (1999). CrossRef
Läkamp, S., Malats, A. i Riera, G. Pourroy, P. Poix, J.L. Dormann, J.M. Greneche, Eur. J. Solid State Inorg. Chem. 32, 159 (1995).
Yamegni-Noubeyo, J.C., Pourroy, G., Werckmann, J., Malats, A. i Riera, P. Poix, J. Am. Ceram. Soc. 79, 2027 (1996). CrossRef
Läkamp, S., Pourroy, G., J. Solid State Chem. 123, 109 (1996). CrossRef
Yamegni-Noubeyo, J.C., Bouakham, T., Pourroy, G., Werckmann, J., Ehret, G., J. Solid State Chem. 135, 210 (1998). CrossRef
Pourroy, G., J. Alloys and Compounds 278, 264 (1998). CrossRef
Pourroy, G., Viart, N., Läkamp, S., J. Magn. Magn. Mater. 203, 37 (1999). CrossRef
Tihay, F., Roger, A.C., Kiennemann, A., Pourroy, G., Catal. Today 58, 263 (2000). CrossRef
R.E. Vandenberghe, E. De Grave, in Mössbauer Spectroscopy Applied to Inorganic Chemistry, edited by G.J. Long, F. Grandjean (Plenum Press, New York, 1989), Vol. 3, pp. 59-182.
Voleník, K., Seberíni, M., Rev. Cienc. Quím. 14, 2 (1983).
Yearian, H.J., Kortright, J.M., Langenheim, R.H., J. Chem. Phys. 22, 1196 (1954). CrossRef
Matijevic, E., Simpson, C.M., Amin, N., Arajs, S., Colloids and Surf. 21, 101 (1986). CrossRef
Gillot, B., Ferriot, J.-F., Dupré, G., Rousset, A., Mater. Res. Bull. 11, 843 (1976). CrossRef
Shirley, D.A., Phys. Rev. B 5, 4709 (1972). APS Link not valid for this citation CrossRef
Robbins, M., Wertheim, G.K., Sherwood, R.C., Buchanan, D.N.E., J. Phys. Chem. Solids 32, 717 (1971). CrossRef
Gillot, B., Domenichini, B., Mater. Chem. and Phys. 47, 217 (1997). CrossRef
Gillot, B., Jemmali, F., Chassagneux, F., Salvaing, C., Rousset, A., J. Solid State Chem. 45, 317 (1982). CrossRef
Djega-Mariadassaou, C., Merceron, T., Dormann, J.L., Porte, M., Renaudin, P., Phys. Stat. Sol. 112, 601 (1989). CrossRef