MOTION OF IXniVIDTAL DOMAIN WALLS 



1029 



of extraneous structure such as surface spikes and pits. It is therefore 

 inipossiblo to show in one picture the whole pattern as diagrammed 

 ill I'ig. 1. However, more detailed pictures of parts of the pattern do 

 show that it is there. The essential features of the pattern on our best 

 sample are shown in Figs. 4 and 5. Fig. 4 shows the stationary wall at 

 one corner, and Fig. 5 shows a section of the movable wall on one leg. 

 Differentiation of the domain walls in Figs. 4 and 5 from the many 

 scratches is not very difficult after one has some experience in such 

 obser\'ations. 



The variation in wall position along the leg shown in Fig. 5 is due to 

 the effects of strains and other imperfections, present even in this care- 

 fully prepared sample, in determining the position of the wall at rest. 



i 



; I 



-0.2 0.2 



H IN OERSTEDS 



Fig. 3 — Hysteresis loop taken on same sample as loop in Fig. 2 after annealing 

 for one hour at 580°C in a magnetic field of approximately 20 oersteds. 



