EFFECT OF DAMPING ON DYNAMIC DISTORTION IN MAGNETIC GARNET MATERIAL

Damping has a large effect on,the dynamic character of domain walls in bubble garnet material with structure within the walls. When a step change in bias field is applied to a wall containing a pi VBL chain or a 2 pi VBL chain, the VBL velocity makes large changes in magnitude for the first 50 nsec when the damping is 0.1 and smoothly changes when the damping is 0.5. Dynamic distortion of 2 pi VBL also makes large swings in magnitude for low damping. Because the wall and VBL velocity as well as 2 pi VBL distortion change so markedly with time for low damping, it is clear-that an increase in damping above the traditional alpha=0.1 is very desirable for material used in a VBL memory.