Magnetization reversal in weakly coupled magnetic patterns

摘要: Abstract Ion irradiation is an original process to pattern the structural and as a consequence magnetic properties of ultra-thin films, down nanometer scale. Patterns dots tracks have been fabricated by focused Ga + ion beam scanned onto Co layer with perpendicular anisotropy. Depending on dose, behaviour nanometric irradiated lines can be tuned from ferromagnetic reduced coercivity paramagnetic. The larger fluence, smaller exchange between or tracks. These systems enabled investigations competition dipolar interactions. For arrays designed high doses only coupled interactions, relaxation proceeds magnetization reversal individual follows power-law time decay. Monte Carlo simulations reproduce this dependence.