Ballistic electron magnetic microscopy: Imaging magnetic domains with nanometer resolution

Abstract
A variation of ballistic electron emission microscopy has been developed to image magnetic structure in thin-film multilayers with nanometer resolution. In studies of nominally uncoupled Co/Cu/Co trilayer films, magnetic domains and domain-wall motion are readily observable with this technique. In the Co/Cu/Co trilayer system magnetic domains are found to occur on an ∼500-nm-length scale and less, while smaller-scale fluctuations in the ballistic electron transport properties of the system are found on an ∼10 nm length scale.