Inductive measurement of ultrafast magnetization dynamics in thin-film Permalloy

Abstract

The ultrafast magnetization phenomena in thin-film Permalloy (Ni81Fe19) was investigated by inductive method. Switching times as short as 200 ps for an inferred 60° rotation were measured. The existence of inductive oscillations long after the application of the field pulse is characteristic of highly underdamped gyromagnetic precession. The data are well fitted to the Landau-Lifshitz equation. Shape-induced magnetization strongly affects the magnetization oscillation frequency.