Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65
MA 20.80: Poster
Montag, 7. März 2005, 14:00–18:00, Poster TU C
Nanoscale Mechanosynthesized Magnesium Ferrite with Enhanced Magnetization — •Vladimir Šepelák1, Ingo Bergmann2, Frank Krumeich3, Dirk Menzel4, and Klaus Dieter Becker2 — 1Center for Solid State Chemistry and New Materials, University of Hannover, 30167 Hannover, Germany; on leave from Slovak Academy of Sciences, Košice, Slovakia — 2Institute of Physical and Theoretical Chemistry, TU Braunschweig, 38106 Braunschweig, Germany — 3Laboratory of Inorganic Chemistry, Swiss Federal Institute of Technology Zurich, 8093 Zurich, Switzerland — 4Institute of Semiconductor Physics and Optics, TU Braunschweig, 38106 Braunschweig, Germany
Nanosized spinel-type ferrites are currently key materials for advancements in electronics, magnetic storage, ferrofluid technology, optoelectronics, and in many bioinspired applications (for example, as drugs carriers for magnetically guided drug delivery and as contrast agents in magnetic resonance imaging). In this contribution, nanocrystalline magnesium ferrite (MgFe2O4) with crystallite size of 8 nm has been synthesized by high-energy milling method from a mixture of α-Fe2O3 and MgO. High-field Mössbauer spectroscopy, X-ray powder diffraction, transmission electron microscopy, and magnetization (SQUID) measurements have been used to investigate the structural and magnetic states of the nanoscale mechanosynthesized spinel ferrite. Several interesting feature are involved in the work, e.g., superparamagnetism and an irreversible magnetic behavior. The observed enhancement of the magnetization in nanosized mechanosynthesized MgFe2O4 is discussed with respect to the non-equilibrium cation distribution and spin canting.