  We study the effect on CPP GMR of changing the order of the layers in a
multilayer. Using a tight-binding simple cubic two band model (s-d),
magneto-transport properties are calculated in the zero-temperature, zero-bias
limit, within the Landauer-Buttiker formalism. We demonstrate that for layers
of different thicknesses formed from a single magnetic metal and multilayers
formed from two magnetic metals, the GMR ratio and its dependence on disorder
is sensitive to the order of the layers. This effect disappears in the limit of
large disorder, where the results of the widely-used Boltzmann approach to
transport are restored.
