Search

Time-resolved magnetic domain patterns of (Co/Pt) and (CoFeB/Pd) multi-layers with a perpendicular magnetic anisotropy are observed by means of magneto-optical microscopy, from which magnetic relaxation curves are determined via a quantitative image analysis. Interestingly, it has been observed that the relaxation processes starting with pre-existing nucleation sites, as well as starting from a fully saturated state, are well explained based on the Fatuzzo–Labrune model, although the pre-existing nucleation sites significantly modify the magnetization reversal behaviors. [ABSTRACT FROM AUTHOR]

Time-dependent magnetic domain patterns of Co/Pt multilayer with a perpendicular magnetic anisotropy has been directly observed by a magneto-optical Kerr microscopy. From our direct domain observation, it is revealed that, when a negative exposure field has been applied after positively saturating the film first, the number of pre-existing nucleation sites decreases as a strength and an applied time of the exposure field increase. It was also observed that pre-existing nucleation sites can speed up the magnetization reversal process by two orders of magnitude, where a strong correlation between the number of nucleation sites and the half-reversal time is found. [ABSTRACT FROM AUTHOR]

Detailed demagnetization process depending on various external field profiles has been investigated using a magneto-optical Kerr/Faraday microscopy for a Co/Pt multilayer film with a perpendicular magnetic anisotropy. By quantitatively analyzing local magnetic domain structures, we propose that it is possible to define a parameter $\eta$ , which represents how well the demagnetization has been carried out microscopically. The degree of demagnetization $\eta$ , defined by a ratio between the final demagnetized image intensity and saturated image intensity, has been experimentally found to significantly reflect the microscopic demagnetization behavior. Dependences of $\eta$ on the maximum amplitude, decreased step size, and effective sweeping rate of alternating demagnetizing field have been systematically investigated together with a direct microscopic observation of magnetic domain structures. [ABSTRACT FROM AUTHOR]