The magnetoresistance of step-edge structures in La0.7Ca0.3MnO3 films was investigated. Step-edge arrays with 200 steps of height 140–200 nm and step separation 20 μm along [110] were fabricated on LaAlO3 substrates by chemically assisted ion-beam etching. Thin La0.7Ca0.3MnO3 films were deposited on the structured substrates by pulsed-laser deposition. Measurements of the large low-field magnetoresistance, the dynamic conductance, and the anisotropic magnetoresistance lead to the proposal of a model of spin-polarized tunneling in a ferromagnet/spin-glass/ferromagnet geometry.

Electrodeposited multilayered nanowires grown within a polycarbonate membrane constitute a new medium in which giant magnetoresistance (GMR) perpendicular to the plane of the multilayers can be measured. These structures can exhibit a perpendicular GMR of at least 22% at ambient temperature. We performed detailed studies both of reversible magnetization and of irreversible remanent magnetization curves for CoNiCu/Cu/CoNiCu multilayered and CoNiCu pulse-deposited nanowire systems with Co:Ni ratios of 6:4 and 7:3 respectively in the range 10 - 290 K, allowing the magnetic phases of these structures to be identified. Shape anisotropy in the pulse-deposited nanowire and inter-layer coupling in the multilayered nanowire are shown to make important contributions to the magnetic properties. Dipolar-like interactions are found to predominate in both nanowire systems. Magnetic force microscope (MFM) images of individual multilayered nanowires exhibit a contrast consistent with there being a soft magnetization parallel to the layers. Switching of the magnetic layers in the multilayered structure into the direction of the MFM tip's stray field is observed.

A set of reference samples for comparing the results obtained with different Magnetic Force Microscopes (MFM) has been prepared. These samples consist of CoNi/Pt magneto-optic multilayers with different thickness. The magnetic properties of the multilayer are tailored in such a way that a very fine stripe domain structure occurs in remanence. On top of this intrinsic domain structure, bits were written thermomagnetically using different laser powers. These samples have been imaged in six different laboratories employing both home-built and commercial magnetic force microscopes. The resolution obtained with these different microscopes, tips and measurement methods varies between 30 and 100 nm.

Magnetostrictive FeCo films (thickness 300 nm) have been produced by RF magnetron sputter deposition. The effects of the substrate, composition and thermal treatment on the structural and magnetic properties of the films have been determined. Structural analysis was performed using transmission electron microscopy and x-ray diffraction. The magnetic properties, including magnetostriction, were determined by the magneto-optical Kerr effect, magnetic force microscopy and strain-modulated ferromagnetic resonance. It is found that the magnetic softness of the films is critically dependent on the texture and strain state of the film. With suitable choices of substrate, composition and thermal treatment, these parameters can be controlled, producing magnetically soft films while maintaining a high magnetostriction. The differential response of the magnetic anisotropy to strain in these films is comparable to the best values achieved by more involved manufacturing processes, such as multilayering, showing excellent potential for their use in magnetic sensors and actuators.

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