Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)

MA 14.23: Poster

Dienstag, 25. März 2003, 15:15–19:15, Zelt

NEEL SPIKES AND BUTTERFLY DOMAINS IN BULK IRON — •Rudolf Schäfer and Sabine Schinnerling — Leibniz Institut für Festkörper- und Werkstoffforschung Dresden, Helmholtzstrasse 20, 01069 Dresden

Libovicky’s precipitation [1] method allows to observe the anatomy of 3-dimensional magnetic domain patterns in bulk FeSi crystals. The volume domains, which are No-dqfrozen-inNo-dq as a precipitation pattern when an Fe12.8at.%Si alloy is annealed at about 850 K, are imaged in a polarization microscope after cutting or polishing the sample. In [2] we have applied this method to a (111) oriented crystal, verifying the existence of a three-dimensional echelon pattern for the first time. Here we present some interesting volume patterns that were found on (100) related bulk crystals. Among them are Nèel spike domains. They lead the magnetic flux around non-magnetic inclusions and are an important source for domain wall pinning. Such spikes have been observed around defects on the surface of bulk crystals since many decades [3]. Here we present their first volume observation. Another example are No-dqbutterflyNo-dq and No-dqmothNo-dq domains [3], which are well known from surface observations on slightly misoriented (100) iron surfaces with a preferred perpendicular magnetization. The internal transversal domains, which help in reducing the magnetostatic energy, are analysed by successively polishing the crystal. [1] S. Libovicky, Phys. Status Solidi A 12 (1972) 539 [2] R. Schäfer and S. Schinnerling, J. Magn. Magn. Mat. 215-216, 140-146 (2000) [3] A. Hubert and R. Schäfer: Magnetic Domains. Springer Verlag (1998)