Dresden 2006 – wissenschaftliches Programm

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MA: Magnetismus

MA 7: Micro- and Nanostructured Magnetic Materials I

MA 7.7: Vortrag

Montag, 27. März 2006, 16:30–16:45, HSZ 03

Intergrain interactions in nanocomposite Fe-Pt alloys — •Julia Lyubina, Kirill Khlopkov, Oliver Gutfleisch, Karl-Hartmut Müller, and Ludwig Schultz — IFW Dresden, Institute for Metallic Materials, P.O. Box 270016, D-01171 Dresden, Germany

The structure and magnetic properties of nanocomposite Fe_100−xPt_x (x=40-60) powders prepared by mechanical alloying followed by annealing are investigated. Different microstuctures were obtained depending on the Pt concentration: a combination of the hard magnetic L1₀ FePt and paramagnetic L1₂ FePt₃ phases, essentially single phase L1₀ FePt and a mixture of L1₀ FePt and soft magnetic L1₂ Fe₃Pt phases. For ferromagnetic phases, a domain structure comprised of elongated interaction domains was observed by magnetic force microscopy (MFM). MFM data and remanence curves were used to provide insight into the nature of intergrain interactions in such powders. The analysis points to strong intergrain coupling in the Fe_100−xPt_x powders. An additional small magnetostatic contribution can be observed for the Pt-rich powders.