Excitation and imaging of precessional modes in soft-magnetic squares

We investigated the high-frequency modes of 40 [micro]m wide, 160 nm thick [Fe.sub.70][Co.sub.8][B.sub.12][Si.sub.10] squares using time-resolved scanning Kerr microscopy. Two modes were identified using pulsed field excitation while the spatial character of the out-of-plane and in-plane magnetization component was investigated using harmonic field excitation. The field dependence of the two modes has been fitted using the Damon--Eshbach model. Index Terms--Ferromagnetic resonance, magnetooptic Kerr effect, spin dynamics, spin waves.