Dynamic magnetization spread in thin magnetic films

Abstract

The dynamic magnetization spread in a uniaxial film sheet excited by a pulse current in a strip line has been investigated by the application of the Landau-Lifshitz equation for distributed systems. A numerical solution is obtained from two coupled nonlinear integrodifferential equations. The key mechanism responsible for the wide spread of magnetization is: Different speeds in the gyromagnetic precession of spins in regions underneath and outside the strip result in nonuniform magnetization distribution which in turn causes propagation of the magnetization change at high speed (10 μm/nsec) through magnetostatic and exchange coupling. Direct measurements on the dynamic magnetization distribution are made with a nanosecond microscopic (3 nsec rise time, 25 μm resolution) Kerr apparatus. Experimental results are in good agreement with analytical predictions. © 1969 The American Institute of Physics.