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This paper presents a computational study of logic devices built from single-domain Co/Pt nanomagnets, where magnetic properties of the dots are engineered by an inhomogenous focused ion beam (FIB) irradiation. We develop a micromagnetic model for such Co/Pt dots and show that their reversal behavior and coupling to neighboring dots can be precisely engineered by the dose and spatial distribution of the irradiation. We demonstrate that magnetic logic circuits and nonvolatile memory devices with attractive performance figures can be built from asymmetrically irradiated dots.

Ferromagnetic Co/Pt films and single-domain magnets are characterized by various types of Extraordinary Hall-Effect (EHE) sensors. The magnetron sputtered multilayer films are annealed and measured in the temperature range of 22 °C ⩽ T ⩽ 75 °C. By focused ion beam (FIB) irradiation, the magnetic properties of the Co/Pt stack are tailored to define both the switching field and the geometry of nanomagnetic single domain dots. A submicron sized EHE-sensor for read-out of field-coupled computing devices is presented. The applied sensing structure is suitable to electrically probe the output states of field-coupled magnetic logic gates. Furthermore, it reveals details on the magnetic properties of submicron-scale single-domain dots and the main measured features are confirmed by micromagnetic simulations. A ‘split-current’ architecture is chosen, where Hall sensing takes place in a single lateral direction, in order to keep field-coupling to adjacent nanomagnets undisturbed. From angular measurements we conclude that the reversal mechanism of the FIB patterned magnetic dots is domain-wall driven. The sensor is a main component needed for integration of nanomagnetic computing units embedded into microelectronic systems.