1. Origin of four-fold anisotropy in square lattices of circular ferromagnetic dots
- Author
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Kakazei, G. N., Pogorelov, Yu. G., Costa, M. D., Mewes, T., Wigen, P. E., Hammel, P. C., Golub, V. O., Okuno, T., and Novosad, V.
- Subjects
Condensed Matter - Materials Science - Abstract
We discuss the four-fold anisotropy of in-plane ferromagnetic resonance (FMR) field $H_r$, found in a square lattice of circular Permalloy dots when the interdot distance $a$ gets comparable to the dot diameter $d$. The minimum $H_r$, along the lattice $<11>$ axes, and the maximum, along the $<10>$ axes, differ by $\sim$ 50 Oe at $a/d$ = 1.1. This anisotropy, not expected in uniformly magnetized dots, is explained by a non-uniform magnetization $\bm(\br)$ in a dot in response to dipolar forces in the patterned magnetic structure. It is well described by an iterative solution of a continuous variational procedure., Comment: 4 pages, 3 figures, revtex, details of analytic calculation and new references are added
- Published
- 2006
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