Influence of Wall Coercivity on Magnetization Process of Stripe Domain in MnBi Films

The domain configuration and the magnetization process in MnBi films are studied with the aid of the magneto-optic Kerr effect. The pattern period or the average width of reversed and unreversed stripe domains as well as the technical magnetization show a hysteresis phenomenon with respect to the external magnetic field. The pattern period for the same net magnetization is shorter for the ascendant magnetization curve than for the descendant one. The hysteresis phenomena including the minor loop of magnetization are well interpreted by a modified stripe domain theory which takes the effect of the domain wall coercivity into consideration.