Regensburg 2002 – wissenschaftliches Programm
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MA: Magnetismus
MA 10: Poster : Dünne Schichten(1-21),Spinabh.Transp.(22-39),Exch.Bias(40-51),Spindyn.(52-55),Mikromag.(56-66),Partikel(67-74),Abb.Verf.(75-77),Oberfl.+Spinelektr.+Elektr.Theo+Mikromag(75-87),PÜ+Aniso+Werkst/Leg.(88-103),Mol.Mag.+N-dim+Messm.+Postdead(104-111
MA 10.64: Poster
Dienstag, 12. März 2002, 15:00–19:00, Bereich A
Sol-gel synthesis of pure magnetic Fe nanoparticles dispersed in alumina matrix — •Yuelong Huang1,2, Desheng Xue1, Yue Ma1,2, Fashen Li1, and Walfgang.R Fahrner2 — 1Key Lab for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China — 2Chair of Electronic Devices, University of Hagen, D-58084 Hagen, Germany
An investigation using the sol-gel method for the successful synthesis of pure Fe-Al2O3 nanocomposites from aluminum isopropoxide precursors and ferric nitrate is described for the first time. The hydrolysis reaction, polymerization reaction, and thermal treatment in hydrogen atmosphere are discussed. In this sol-gel process, the solution temperature and its pH value are strictly controlled in order to get clear sols and transparent gels, i.e. to avoid the hydrolysis precipitation. Extensive composite homogeneity and dispersion are achieved. The structure and morphology of the resulting nanocomposites are characterized by using X-ray diffraction and transmission electron microscopy. The magnetic properties and hyperfine interactions are studied by employing vibrating sample magnetometer and Mössbauer spectroscopy. The FeAl2O4 is found to be an intermediate phase between alpha-Fe2O3 and alpha-Fe. The magnetic properties of iron nanoparticles are found much different from bulk Fe. The success of the sol-gel route provides a new low temperature and low budget way to obtain magnetic Fe nanoparticles embedded in non-magnetic Al2O3 matrix.
Keywords: nanocomposites; Fe-Al2O3; sol-gel; x-ray diffraction; Mössbauer spectra; transmission electron microscopy.