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MA: Magnetismus
MA 29: Magnetic Thin Films IV
MA 29.7: Talk
Thursday, March 30, 2006, 16:45–17:00, HSZ 03
Synthetic metamagnetism: reorientation effects and multidomain states in perpendicular antiferromagnetic superlattices — •U.K. Rößler and A.N. Bogdanov — IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany
Recently synthesized antiferromagnetically coupled multilayers
with strong perpendicular magnetic anisotropy, like [CoPt]/Ru,
[CoPt]/NiO, Co/Ir, or Fe/Au, represent a new class of magnetic materials.
These synthetic metamagnets are characterized by a cascade of metamagnetic phase
transitions, extended regions of metastable states and complex
multidomain structures [1,2]. Within a phenomenological theory,
we have classified and analyzed the wide variability
of magnetic field-driven reorientation transitions and accompanying
multidomain states in these synthetic metamagnets.
In contrast to other bulk and nanomagnetic systems,
the magnetic states are determined by a close competition
between antiferromagnetic interlayer exchange
and dipolar couplings. The theory of this phenomenon
allows to explain the unusual switching processes and
specific transformation of the domain patterns observed
in these synthetic metamagnets.
[1] O. Hellwig et al., Nature Mater. 2 (2003) 112. [2] U. K. Rößler, A. N. Bogdanov, JMMM 269 (2004) L287.