Direct measurement of domain wall coercive field

Abstract

Reproducible and well defined small hysteresis loops of rhomboid shape were measured on thin uniaxial magnetic garnet films. Observation of the domain structure showed that the change in the magnetic moment described by these loops was due solely to elementary translations of domain walls. The authors have called the half-width of these loops the domain wall coercive field, Hdw; this parameter differed substantially from the half-width, Hc of the major saturation-to-saturation hysteresis loops. They called the rhomboid small loops the domain wall coercive loops (DWCL) and showed that Hdw obtained from DWCL was identical to the coercive field value measured by the low frequency domain wall oscillation method. The slope of DWCL coincided with the initial susceptibility of stripe domain structures and thus made it possible to calculate the basic parameters of the sample, giving results in agreement with other established methods of measurement of these parameters.