Polarized neutron study of antiferromagnetic ordering in Dy/Er superlattices

Dy/Er superlattices, grown on sapphire, exhibit a succession of magnetic phases. Below the ordering temperature of dysprosium, the helix of dysprosium propagates coherently through paramagnetic erbium. At low temperature, dysprosium becomes ferromagnetically ordered in each layer but the layers are antiferromagnetically stacked. A polarized neutron scattering study of the low-temperature phase is presented. It shows that the antiferromagnetic peaks are never purely spin-flip. (orig.)