Ultrafast excitation of matter can violate Curie's principle that the symmetry of the cause must be found in the symmetry of the effect. For instance, heating alone cannot result in a deterministic reversal of magnetization. However, if the heating is ultrafast, it facilitates toggle switching of magnetization between stable bit-states without any magnetic field.
View Article and Find Full Text PDFThe magnetic properties of NiO/Co/Pt as a function of Co layer thickness were investigated by polar magneto-optical Kerr effect (PMOKE) (magnetometry and microscopy) and Brillouin Light Scattering (BLS) spectroscopy. PMOKE measurements revealed strong surface anisotropy (1.8 mJ/m) favoring perpendicular magnetic anisotropy and asymmetric domain wall propagation explained by anticlockwise chirality.
View Article and Find Full Text PDFRecent results showed that the ferrimagnetic compensation point and other characteristic features of Tb/Co ferrimagnetic multilayers can be tailored by He ion bombardment. With appropriate choices of the He ion dose, we prepared two types of lattices composed of squares with either Tb or Co domination. The magnetization reversal of the first lattice is similar to that seen in ferromagnetic heterostructures consisting of areas with different switching fields.
View Article and Find Full Text PDFWe show that it is possible to engineer magnetic multidomain configurations without domain walls in a prototypical rare-earth-transition-metal ferrimagnet using keV He^{+} ion bombardment. We additionally show that these patterns display a particularly stable magnetic configuration due to a deep minimum in the energy of the system caused by flux closure and a corresponding reduction of the magnetostatic energy without an increase in energy by exchange and anisotropy terms across the walls. This occurs because light-ion bombardment affects an element's relative contribution to the properties of the ferrimagnet differently.
View Article and Find Full Text PDFModifications of magnetic and magneto-optical properties of Pt/Co(d )/Pt upon Ar irradiation (with energy 1.2, 5 and 30 keV) and fluence, F at the range from 2 · 10-2 · 10 Ar cm) were studied. Two 'branches' of increased perpendicular magnetic anisotropy (PMA) and enhanced magneto-optical response are found on 2D (d , F) diagrams.
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