Apparent sixfold configurational anisotropy and spatial confinement of ferromagnetic resonances in hexagonal magnetic antidot lattices V. N. Krivoruchko and A. I. Marchenko Journal of Applied Physics 109, (2011) Speaker Iryna Kulagina

High density magnetic data storage 2

Model A 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. 3

Equations The continuum approximation: the magnetic medium is characterized by the magnetization vector that depends on both space and time. The LLG equation: The effective field: 4

Static Magnetic Structure 5

Magnetization Dynamics 6

Conclusions 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. 7

Thank you for attention 8