On optical magnetization curves of periodic domain structures

Abstract

The magneto-optical hysteresis curves (transmitted light intensity versus field) of transparent films with magnetization perpendicular to the surface were measured and their difference from the true magnetic hysteresis curves (magnetization versus field) is discussed. The magnetic hysteresis curves of stripe domain structures can easily be obtained from the magneto-optical ones by plotting the difference of the optical signals corresponding to opposite directions of the same value of the sample magnetization. This difference is shown to be proportional to the relative magnetization not only in the case of the pure and simple experiment assumed by the considered theory but even in some more complicated experimental arrangements. With bubble domain lattices, however, when the symmetric measurement cannot be easily performed, the use of the presented formulas for recalculation of the optically measured curves is recommended.