Time- and vector-resolved magneto-optical Kerr effect measurements of large angle precessional reorientation in a 2×2 μ m2 ferromagnet

Abstract

The precessional dynamics of a 2×2 μm2 CoFe/NiFe (4.6 nm) element stimulated by an in-plane pulsed magnetic field have been investigated using time- and vector-resolved Kerr microscopy measurements and micromagnetic simulations. The time-resolved signals were normalized to in-plane hysteresis loops obtained from the patterned material, and suggest that the magnetization reorients through an angle of 100°±10°. The simulations reveal that only the magnetization of the center region undergoes large angle reorientation, while the canted magnetization at the edges of the element remains pinned. An enhanced Gilbert damping parameter of 0.1 was required to reproduce the experimentally observed Kerr signals.