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This paper investigates the relationship among interlayer exchange coupling (IEC), Dzyaloshinskii–Moriya interaction (DMI), and multilevel magnetization switching within a Co/Pt/Co heterostructure, where varying Pt thicknesses enable control over the coupling strength. Employing Brillouin Light Scattering to quantify the effective DMI, we explore its potential role in magnetization dynamics and multilevel magnetization switching. Experimental findings show four distinct resistance states under an external magnetic field and spin Hall effect related spin current. We explain this phenomenon based on the asymmetry between Pt/Co and Co/Pt interfaces and the interlayer coupling, which, in turn, influences the DMI and subsequently impacts the magnetization dynamics. Numerical simulations, including macrospin, 1D domain wall, and simple spin wave models, further support the experimental observations of multilevel switching and help uncover the underlying mechanisms. Our proposed explanation, supported by magnetic domain observation using polar-magnetooptical Kerr microscopy, offers insights into both the spatial distribution of magnetization and its dynamics for different IECs, thereby shedding light on its interplay with DMI, which may lead to potential applications in storage devices. [ABSTRACT FROM AUTHOR]

Recent developments in the observation of magnetic domains and domain walls by wide-field optical microscopy based on the magneto-optical Kerr, Faraday, Voigt, and Gradient effect are reviewed. Emphasis is given to the existence of higher order magneto-optical effects for advanced magnetic imaging. Fundamental concepts and advances in methodology are discussed that allow for imaging of magnetic domains on various length and time scales. Time-resolved imaging of electric field induced domain wall rotation is shown. Visualization of magnetization dynamics down to picosecond temporal resolution for the imaging of spin-waves and magneto-optical multi-effect domain imaging techniques for obtaining vectorial information are demonstrated. Beyond conventional domain imaging, the use of a magneto-optical indicator technique for local temperature sensing is shown. [ABSTRACT FROM AUTHOR]

The results of combined (experimental, analytical, and micromagnetic simulations) studies on the evolution of magnetization states and processes in ultrathin films and multilayered systems are presented. We show ways to manipulate magnetization distributions in ultrathin magnetic single or multilayers by tuning: the thickness of the magnetic layer, the thickness of either the non-magnetic cap or spacer layer, the magnetic anisotropy, and the geometrical constrictions of the system. In ultrathin magnetic films, both the magnetization distribution and the critical thickness of the magnetization reorientation phase transition (RPT) between perpendicular and in-plane states can be also controlled by post-growth treatments, e.g., by either ion or light irradiation. By changing the geometrical parameters of the nanostructure, as well as by an applied external magnetic field, one can tune magnetic domain sizes in a giant range (of a few orders of magnitude) and induce the RPT. Transitions between two- and three-dimensional magnetization distributions are discussed. [ABSTRACT FROM AUTHOR]

Currently, much attention is being paid to patterned multilayer systems in which there exists a perpendicular magnetic anisotropy, because of their potential applications in spintronics devices and in a new generation of magnetic storage media. To further improve their performance, different patterning techniques can be used, which render them suitable also for other applications. Here we show that He+ 10 keV and Ar+ 100 keV ion bombardment of (Ni80Fe20-2 nm/Au-2 nm/Co-0.6 nm/Au-2 nm)10 multilayers through colloidal mask enables magnetic patterning of regularly arranged cylindrical magnetic domains, with perpendicular anisotropy, embedded in a non-ferromagnetic matrix or in a ferromagnetic matrix with magnetization oriented along the normal. These domains form an almost perfect two-dimensional hexagonal lattice with a submicron period and a large correlation length in a continuous and flat multilayer system. The magnetic anisotropy of these artificial domains remains unaffected by the magnetic patterning process, however the magnetization configuration of such a system depends on the magnetic properties of the matrix. The micromagnetic simulations were used to explain some of the features of the investigated patterned structures. [ABSTRACT FROM AUTHOR]