Observation of Antiparallel Magnetic Order in Weakly Coupled Co/Cu Multilayers

J. A. Borchers, J. A. Dura, J. Unguris, D. Tulchinsky, M. H. Kelley, C. F. Majkrzak, S. Y. Hsu, R. Loloee, W. P. Pratt, J. Bass
1999 Physical Review Letters  
Polarized neutron reflectivity and scanning electron microscopy with polarization analysis are combined to determine the magnetic structure of Co(6 nm)/Cu(6 nm) multilayers. These data resolve a controversy regarding the low-field state of giant-magnetoresistive (GMR) multilayers with weak coupling. As-prepared samples show a strong antiparallel correlation of in-plane ferromagnetic Co domains across the Cu. At the coercive field, the Co domains are uncorrelated. This irreversible transition
more » ... sible transition explains the decrease in magnetoresistance from the as-prepared to the coercive state and indicates that the as-prepared state best represents the antiparallel configuration assumed in GMR analysis. For both states, the Co moments reside in domains with inplane sizes of § P
doi:10.1103/physrevlett.82.2796 fatcat:thf2d7zggzgfveci7tenjanjdy