Origin of the temperature dependence of the giant magnetoresistance in magnetic multilayers

The temperature dependence of the giant magnetoresistance (GMR) and layer magnetizations has been investigated for uncoupled single Co/Cu/${\mathrm{Fe}}_{20}$ ${\mathrm{Ni}}_{80}$ trilayers. Below 100 K, the GMR amplitude is found to decay as ∼${\mathit{T}}^2$, whereas above 100 K a weaker temperature dependence is exhibited. The temperature dependence of the average layer magnetizations is found to be uncorrelated with that of the GMR. We show that a simplified two-current model can explain the main features of the behavior observed for our samples and other multilayer systems, provided that spin mixing is included.