This thesis presents recent developments in magnetic coupling phenomena of ferrimagnetic rare-earth transition-metal Tb-Fe alloys and coupled systems consisting of ferri-/ferromagnetic heterostructures. Taking advantage of the tunability of the exchange coupling between ferrimagnetic and ferromagnetic layers by means of stoichiometry of the Tb-Fe layer, the variable number of repetitions in the Co/Pt multilayer as well as the thickness of an interlayer spacer, it is demonstrated that large perpendicular unidirectional anisotropy can be induced at room temperature. This robust perpendicular exchange bias at room temperature opens up a path towards applications in spintronics.
Cuprins
Introduction.- Thin Amorphous Fe-Tb Alloy Films.- Co/Pt Multilayers.- Exchange-Bias Effect in F/FI Rare-Earth-Transition-Metal Heterostructures.- Experimental Techniques.- Magnetic Order in Thin Fe-Tb Films.- Percolated Fe-Tb Nanodot Arrays – Exchange Interaction and Magnetization Reversal.- Interfacial Exchange Coupling in Heterostructures of Fe-Tb Alloy Films and Co/Pt Multilayers.- Interlayer Exchange Coupling Through Pt Spacer Layers in Fe-Tb/Pt/[Co/Pt] Heterostructures.- Conclusion.