Picosecond magnetization dynamics in nanomagnets: Crossover to nonuniform precession
Physical Review B
American Physical Society
The picosecond magnetization dynamics of arrays of square Ni88Fe12∕Co80Fe20 bilayer nanoelements were studied by optical pump-probe measurements. Experimentally observed modes were found to fall upon two branches, with a crossover from the high- to low-frequency regime as the element size was reduced to less than 220 nm. Micromagnetic simulations revealed that the branches are associated with center and edge modes. The edge mode is found to dominate as the element size is reduced so that the magnetic response to a pulsed field becomes less spatially uniform.
Copyright © 2005 The American Physical Society
Vol. 71 (22), article 220409(R)