Observation of Precessional Magnetization Dynamics in L10-FePt Thin Films with Different L10 Order Parameter Values

Fast magnetization precession was observed in L10-FePt thin films with different L10 order parameter values by all optical pump–probe technique. Precession frequency was varied widely for the films with different order parameter, which is due to large difference in perpendicular magnetic anisotropy. Gilbert damping constant (α) was estimated from relaxation time as apparent damping. Clear difference in α was not observed with different perpendicular magnetic anisotropy.