Millimicrosecond Magnetization Reversal in Thin Magnetic Films

Abstract

From ferromagnetic resonance experiments and from calculations based on the modified Landau-Lifschitz equation, switching times for the coherent rotation of the magnetization in thin, permalloy-type films have been predicted to lie in the range of 1 mi1limicrosecond. ¹ First measurements by D.O. Smith et al, ² utilizing a travelling-wave oscilloscope with a response time of 2 mµsec, indicated switching times of about 3 mµsec. In this communication, first results of advanced millimicrosecond measurements are reported. These were obtained by using special pulse equipment including a sampling oscilloscope, ^3,4 with an over-all response time of about 0.5 mµsec. Flux changes as fast as 1.5 mµsec could be observed, for not only the longitudinal flux component, ⁵ but also, for the first time, the transverse one.