ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Co–Cu superlattices grown by MBE in the (111) orientation show weak or nonexistent interlayer exchange coupling, yet several groups have observed large high-field magnetoresistance signals in excess of 30%. In the present work, we address some of the questions relating to GMR and the interlayer coupling by studying samples with atomically abrupt interfaces, as probed by real-time RHEED techniques, HRTEM, and spin-echo NMR. We propose that the lowered dimensionality of the structure leads to an enhancement of the scattering of conduction electrons from paramagnetic interfaces obeying a Langevin-like saturation at very high fields, well beyond the switching field of the Co layers. Scaling between the GMR and thermopower measurements suggests that a spin-dependent density of states at the Co–Cu interfaces is responsible for the observed magnetotransport behavior in these samples, rather than antiferromagnetically coupled Co layers.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.355447
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