Magnetization measurements on the nanometer-scale

We calibrated the magnetic tip of a magnetic force microscope within the point-probe approximation, using lithographically prepared Ω-shaped current carrying gold rings of different radii R. Probing with this tip a nanosized single domain Co/Pt multilayer dot with perpendicular anisotropy allows quantitative determination of the z-component of the magnetization and the hysteresis loop of the dot.