Co/Cu͑111͒ multilayers, ͓Co͑17 Å͒/Cu͑8 ÅϽt Cu Ͻ14 Å͔͒ 30 , have been prepared on Co͑70 Å͒ buffer layers on Al 2 O 3 ͑0001͒ substrates by molecular beam epitaxy. From the longitudinal and transverse magnetoresistance ͑MR͒ measurements, it is observed that MRs consist of two components with a small anisotropic MR ͑Ͻ2%͒ component at low field sitting on top of the giant MR ͑up to 22%͒ component at higher field. The AMR effect strongly correlates with the abundance of hcp stacking of Co, which

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... to decrease with the increasing of Cu spacer thickness. The AMR saturation fields ͑1-3 kOe͒ coincides with those of the magnetization. It is suggested that the observed AMR effect is due to scattering from the hcp-phase Co layers in the multilayers. This together with the large saturation field ͑30-40 kOe͒ obtained from the entire MR curves indicate that the observed GMR effect may result from the Co-Cu interfacial spin-dependent scattering.