FMR Study of Permalloy Films Patterned Into Square Lattices of Diamond Antidots

We have performed broadband (10 MHz-14 GHz) ferromagnetic resonance measurements on permalloy thin films patterned with square lattices of diamond-shaped antidots of variable size and separation. We observe remarkably reproducible mode structures in the low-frequency, hysteretic regime in which various domain wall patterns and unsaturated magnetization textures exist and are strongly affected by the geometry of the antidot lattice. The magnetic field, frequency and angular dependences of the observed modes (some not previously reported) are in good agreement with recently developed micromagnetic simulations. The mode reproducibility is attributed to a reproducible evolution of domain wall textures governed by their pinning to antidot edges. We conclude variations of antidot size, shape and spacing can be used to control magnetic reversal, domain wall pinning and spin wave mode structure.