Ballistic electron magnetic microscopy: Imaging magnetic domains with nanometer resolution

A variation of ballistic electron emission microscopy has been developed to image magnetic structure in thin-film multilayers with nanometer resolutio n. In studies of nominally uncoupled Co/Cu/Co trilayer films, magnetic doma ins and domain-wall motion are readily observable with this technique. In t he Co/Cu/Co trilayer system magnetic domains are found to occur on an simil ar to 500-nm-length scale and less, while smaller-scale fluctuations in the ballistic electron transport properties of the system are found on an simi lar to 10 nm length scale. (C) 1999 American Institute of Physics. [S0003-6 951(99)03933-9].