Deutsche Tagung f ¨ur Forschung mit ... - SNI-Portal

Magnetismus Poster: Do., 13:00–15:30 D-P241
Real space observation of dipolar interaction in arrays of iron and permalloy
elements
Guido Meier 1 , Markus Bolte 1 , Rene Eiselt 1 , Ulrich Merkt 1 , Dong-Hyun
Kim 2 , Peter Fischer 2
1 Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität
Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany – 2 Center for X-Ray Optics,
Lawrence Berkeley National Lab, 1 Cyclotron Road, Mail Stop 2R0400, Berkeley, California
94720
Square lattice arrays of thin micro- and nanoelements of iron and permalloy are investigated
by magnetic transmission x-ray microscopy. The influence of dipole interaction
is analyzed by varying the interelement distance, the angle of the applied magnetic
field, and the lattice configuration. For the iron squares the magnetostatic field caused
by inter-element interaction leads to a substantial stabilization of the center elements
of the array [1] comparable to the magnetization process previously found by numerical
solution of the Landau-Lifshitz equation for magnetic dot arrays. Micromagnetic
simulations show, that for high field strengths the dipolar interaction is collinear with
the external field, while in the low-field-regime the strayfields have significant perpendicular
components leading to a complex reversal mechanism.
[1] Markus Bolte, René Eiselt, Guido Meier, Dong-Hyun Kim, and Peter Fischer, J.
Appl. Phys. 99, 08H301 (2006).
Fig. 1: MTXM images of arrays
of Fe microelements with
(a) 200 nm, (b) 600 nm, (c)
800 nm, and (d) 2000 nm interelement
spacing in a magnetic
field of µ0H = +8.7 mT.
Its direction is indicated by
the arrow. The inset in (d) is
an enlarged zoom of one microelement
of this array with
the magnetization indicated
by arrows.