Current-induced realignment of magnetic domains in nanostructured Cu/Co multilayer pillars

We have developed a nanofabrication technique to facilitate current-perpendicular-to-plane transport measurements on magnetic multilayer pillar structures with diameters as narrow as 100 nm-a size scale at which the reversal of individual domains within the ferromagnetic layers may be detected. When large currents are passed through such pillars, the Oersted field produced by the current can affect the orientation of the magnetic moments of the layers. In pillars ranging from 250 to 500 nm, a stack of alternating hard and soft ferromagnetic layers can controllably be switched between high and low resistance states via this mechanism. (C) 2000 American Institute of Physics. [S0003-6951(00)00503-9].