T. Kleinefeld et al., MICROMAGNETIC PROPERTIES AND DOMAIN DYNAMICS OF COPT THIN-FILMS, Journal of magnetism and magnetic materials, 148(1-2), 1995, pp. 249-250
We have studied the magnetization reversal processes of thin CoPt allo
y films by using domain pattern analysis techniques. By means of polar
ization microscopy based on the polar magnetooptic Kerr effect we were
able to investigate static and dgnamic properties of the magnetizatio
n reversal processes in Co28Pt72 alloy samples in the thickness range
from 40 to 300 Angstrom. In correlation to the film thickness we found
a transition from domain wall motion dominated reversal to nucleation
dominated behavior. Our micromagnetic model reveals that the occurenc
e of local demagnetizing fields is the key to describe the observed re
versal processes. Furthermore we found evidence for fractality in the
magnetic domain pattern. The motion of domain walls is characterized b
y wall jaggedness, which obeys scaling laws predicted by the theory of
directed percolation.