Magnetic depth profiling Co/Cu multilayers to investigate magnetoresistance (invited)

The magnetic microstructure responsible for the metastable high resistance state of weakly coupled, as-prepared [Co(6 nm)/Cu(6 nm)](20) multilayers wa s analyzed using polarized neutron reflectivity and scanning electron micro scopy with polarization analysis (SEMPA). This article focuses and expands on the SEMPA measurements. In multilayer structures such as these, SEMPA ca n be combined with ion milling to directly image the layer-by-layer magneti zation and quantitatively depth profile the interlayer magnetic domain corr elations. We found that in the as-prepared Co/Cu multilayer, the domains ar e about 1 mu m in size and the magnetizations in adjacent layers are almost completely oppositely aligned. The relative magnetoresistance derived from this measured degree of anticorrelation is in agreement with the measured magnetoresistance. (C) 2000 American Institute of Physics. [S0021-8979(00)2 0208-9].