Characterization and magnetic properties of Sm- and Gd-substituted CoFe2O4 nanoparticles prepared by forced hydrolysis in polyol
| Autor: | Marie-Joseph Vaulay, F. Herbst, A.-L. Joudrier, Souad Ammar, Fernand Fiévet, Leila Samia Smiri, Mathieu Artus, L. Ben Tahar |
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| Rok vydání: | 2007 |
| Předmět: |
Materials science
Magnetism Mechanical Engineering Analytical chemistry Nanoparticle Hematite Atmospheric temperature range Condensed Matter Physics Crystallography symbols.namesake Mechanics of Materials Ferrimagnetism visual_art X-ray crystallography visual_art.visual_art_medium symbols General Materials Science Raman spectroscopy Superparamagnetism |
| Zdroj: | Materials Research Bulletin. 42:1888-1896 |
| ISSN: | 0025-5408 |
| DOI: | 10.1016/j.materresbull.2006.12.014 |
| Popis: | Pure nanoparticles of the CoFe{sub 2-x}RE{sub x}O{sub 4} (RE = Gd, Sm; x = 0.0, 0.1) system have been prepared by forced hydrolysis in polyol. The insertion of Sm{sup 3+} and Gd{sup 3+} cations into the cobalt ferrite structure has been investigated. X-ray micro-analysis (EDX) shows that the RE contents are close to the nominal ones. X-ray diffraction (XRD) evidences a cell size increase with slight distortions in the spinel-like lattice indicating the entrance of RE{sup 3+} ions. Micro-Raman spectroscopy confirms the cubic inverse-spinel structure and rules out the existence of impurities like hematite. Magnetic measurements (SQUID) show important differences in the magnetic properties of the unsubstituted and substituted particles. All the particles are superparamagnetic at room temperature and ferrimagnetic at low temperature. However, their main magnetic characteristics appear to be directly dependent on the RE content. |
| Databáze: | OpenAIRE |
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