Thermal variation of magnetotransport properties of Co/Cu magnetic multilayers

Abstract Thermal variation and dependence on Cu-layer thickness t Cu ( t Cu =7.6–25.7 A) of magnetoresistance (MR) and the magnetization (M) of [Co(10.2 A)/Cu( t Cu )] 25 magnetic multilayers (MMLs) have been measured between 4.2 and 300 K. So as long as the magnetization of adjacent Co layers are aligned antiparallel, the MR increases with decreasing temperature. This temperature dependence becomes weak as the antiparallel coupling weakens, and it is almost temperature-independent for samples with t Cu where the magnetization is aligned parallel. The temperature dependence of MR for t Cu =11.4 A, for which the coupling crosses over from antiparallel to parallel, is complex.