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Electron scattering mechanisms within metallic multilayers are affected by both structural and magnetic disorders. Off-specular x-ray scattering has long been used to probe the structural interfaces, and it is only recently that it has been applied to the study of magnetic disorder. We compare the resonant magnetic x-ray scattering with off-specular neutron studies from magnetron-sputtered Co/Cu and Co/Ru multilayers grown at the second antiferromagnetic coupling peak. Both techniques yield similar results for the Cu system, and a simple domain model can be applied to extract the magnetic interface morphological parameters. For the Cu system, the in-plane correlation length is field dependent and is 880 ± 20 Å after saturation along the hard axis, but increases to 7000 ± 100 Å after saturation along the orthogonal easy axis. Both systems show strong out-of-plane correlations in both the structural and magnetic disorders. In all cases, the out-of-plane correlation length for the structural interfaces is 200-250 Å, but the ratio of the magnetic to structural correlations length is dependent on the magnitude of the exchange coupling and ranges from 0.4 to 1.4. [ABSTRACT FROM AUTHOR]

In this article we present a detailed investigation of the structural and magnetic properties of exchange biased NiFe (ferromagnet)/FeMn (antiferromagnet) thin films. The influence of the shape anisotropy on exchange bias and the magnetization reversal mechanism in a sample with patterned lines is compared with a continuous two-dimensional reference sample. Polarized neutron reflectivity (PNR) is employed to study the magnetization reversal by analyzing the spin-flip and non-spin-flip reflectivities. PNR measurements show that the magnetization reversal in the reference two-dimensional film and patterned lines is by domain wall motion rather than coherent rotation of magnetization. [ABSTRACT FROM AUTHOR]

Carefully controlled interfaces between two materials can give rise to novel physical phenomena and functionalities not exhibited by either of the constituent materials alone. Modern synthesis methods have yielded high-quality heterostructures of oxide materials with competing order parameters. Although magnetic correlations at the interface are expected to be important in determining the macroscopic properties of such systems, a quantitative determination of the interfacial magnetization profile has thus far not been reported. Here we examine superlattices composed of the half-metallic ferromagnet La2/3Ca1/3MnO3 and the high-temperature superconductor YBa2Cu3O7 by absorption spectroscopy with circularly polarized X-rays and by off-specular neutron reflectometry. The resulting data yield microscopic insight into the interplay of spin and orbital degrees of freedom at the interface. The experiments also reveal an extensive rearrangement of the magnetic domain structure at the superconducting transition temperature. This methodology establishes an incisive probe of the interplay between competing electronic order parameters in oxide heterostructures. [ABSTRACT FROM AUTHOR]

We demonstrate, using spin polarized neutron reflectivity measurements, that one can form a large stack of magnetically decoupled spin-membranes of Gadolinium ions and reduce the effect of the substrate substantially to study short-range two-dimensional (2D) ferromagnetic ordering. No spontaneous magnetization was observed in these membranes as the magnetic field was applied along an in-plane direction. The results are consistent with theoretical predictions of 2D in-plane spin systems having strong interplay of exchange, magneto-crystalline anisotropy and dipolar interactions. These metal–organic multilayer films will enable us to verify various theoretical predictions regarding spin-fluctuations in 2D systems using conventional magnetic measurements and neutron scattering studies. [ABSTRACT FROM AUTHOR]