Articles written in Pramana – Journal of Physics
Volume 71 Issue 5 November 2008 pp 895-895 Invited talks (Abstracts only)
Magnetic thin film systems and laterally patterned magnetic media are the basis of spintronic devices for information technology. In this contribution, we will show that neutron scattering under grazing incidence with polarization analysis is able to provide unique depth resolved information on magnetization, magnetic correlations and magne-tization dynamics relevant for basic and applied research on nanostructured magnetic materials.
It is well established that specular neutron reflectivity with polarization analysis from thin film systems and multilayers provides layer-resolved information on interface rough-ness and on the laterally averaged magnetization. Off-specular diffuse scattering with polarization analysis gives access to lateral correlations, i.e. the detailed interface morphology, the magnetic order of nanoscale objects (stripes or islands), the magnetic fluctuations or domain structure. Depending on the scattering geometry – reflectometry or grazing incidence small angle neutron scattering (GISANS) – correlations on lateral length scales from the nanometer up to the 100 micrometer range become accessible. Close to total reflection, kinematical scattering theory breaks down and dynamical effects have to be taken into account. Simulations in the distorted wave Born approximation (DWBA) allow one to extract quantitative parameters for a statistical model description.
On several examples we will demonstrate the power of the method – from the magnetic fluctuations in remanent sputtered films via the magnetic structure of rare earth multilayers with competing interactions to the remagnetization process of exchange bias systems or the domain structures of laterally patterned giant magnetoresistance multilayers. Finally we will give an outlook on what will be possible on next generation instruments such as the magnetism reflectometer MARIA of the Juelich Centre for Neutron Science (JCNS) at FRM-II.
Volume 80 Issue 4 April 2013 pp 701-711
Depth-sensitive polarized neutron scattering in specular and off-specular mode has recently revealed that perpendicular field cycling brings about a modification in the interfacial magnetization of a trained exchange coupled interface. We show here by various model fits to our neutron reflectivity data that a restoration of the untrained state is not possible in the case of our polycrystalline multilayer specimen. This is due to the magnetic moment at the interface induced only after perpendicular field cycling, changing the initial field-cooled state.
Volume 93 | Issue 5
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