Apparent sixfold configurational Apparent sixfold configurational anisotropy and spatial anisotropy and spatial

confinement of ferromagnetic confinement of ferromagnetic resonances in hexagonal resonances in hexagonal magnetic antidot latticesmagnetic antidot lattices

V. N. Krivoruchko and A. I. Marchenko

Journal of Applied Physics 109, 0083912 (2011)

Speaker Iryna Kulagina

High density magnetic data High density magnetic data storagestorage

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ModelModelA lattice of magnetic antidots that represent holes in a thin ferromagnetic film of thickness d.

The circular antidots have radius r and a two-dimensional periodic hexagonal lattice with lattice period a.

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EquationsEquationsThe continuum approximation: the magnetic medium is characterized by the magnetization vector that depends on both space and time.

The LLG equation:

The effective field:

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)],(),([),(),(),(),(

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trHtrMtrMM

trHtrMdttrdM

effeff

eff ex an demH H H H H 20( ) ( ) ( / ) ( )exH r M r M M r

3 3 3 40( ) [ ( ) ( ) ( ) ] /an x x y y z zH r K M r e M r e M r e M

3 3

( ( '))( ') ( ( ') )( ')( ) ' '

' 'dem V s

M r r r M r n r rH r dr ds

r r r r

Static Magnetic StructureStatic Magnetic Structure

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Magnetization DynamicsMagnetization Dynamics

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ConclusionsConclusions It was found that the competition between the short-range exchange interaction and long-range dipolar coupling leads to a nonuniform equilibrium magnetic state. The periodic antidot pattern determines the observed domain structure and introduces a configurational anisotropy. The magnitude of the induced anisotropy increases as a ratio of the hole radius to the lattice period increases.

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Thank you for

attention

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