Most important is the role of the interface roughness in case of contact with a ferromagnetic layer. The scaling of the Néel temperature with thickness, the critical thickness for the onset of SDW order, the orientation of the SDW wave vector in different environments and the enhancement of SDW order due to proximity effects are extensively discussed. The emphasis is more on SDW order in different confined environments than on exchange coupling. After a brief introduction to the basic properties of bulk Cr, this review provides an overview of the SDW magnetism in thin Cr films, starting with surface properties and continuing with the discussion of Cr films of various thickness. While the incommensurate SDW magnetism and the Néel temperature are well established for bulk Cr, the question arises of how these properties are altered in thin films and superlattices either due to dimensionality effects or due to proximity with the ferromagnetic or paramagnetic boundary layers. The spin density wave (SDW) magnetism of thin epitaxial Cr films has recently become the focus of interest because of its mediating role in exchange coupled superlattices. It is shown that good quality neutron diffraction data can be obtained and that most of the finer details of the phase transitions, and the associated changes in crystallographic parameters in these electrodes, can be captured.

The effectiveness of cell is demonstrated by tracking the neutron diffraction patterns during the charging of graphite/LiCoO2 and graphite/LiMn2O4 cells. The in-situ cell has also been designed for easy assembly and to facilitate rapid experiments.

This has been facilitated by the use of single crystal (100) Si sheets as casing material and the planar cell configuration, giving improved signal-to-noise ratio relative to other casing materials. Diffraction patterns that are Rietveld-refinable could be obtained simultaneously for all the electrodes, which demonstrates that the cell is best suited to explore electrode phase transitions driven by the lithiation and delithiation processes. The design and performance of a novel in-situ electrochemical cell that greatly facilitates the neutron diffraction study of complex phase transitions in small volume electrodes of Li-ion cells, is presented in this work.

Quartz zero background plates