Toward X-ray reflectivity measurements of μm-sized samples

Today, X-ray reflectivity (XRR) is limited to model surfaces employing mm-sized samples. On the other hand, the extent of real surfaces in applications (e.g., Li-ion batteries), which need improved fundamental understanding, is several hundreds of nm to tens of µm. Towards this end, the aim of this proposal is to develop a methodology for (low-angle) XRR of µm-sized samples by employing the nm-sized X-ray beams uniquely available at ID01 of ESRF-EBS. We will systematically carry out proof-of-concept and benchmark XRR measurements of several model µm-sized samples and compare the results to complementary XRR measurements of the respective mm-sized standard samples. The samples are plate-like Al2O3 single-crystal particles coated by 2 nm Ti and 20 nm Au such that well-defined Kiessig fringes are expected (ideal for benchmark measurements). Such a development will be useful for a large user community and be highly impactful for ESRF-EBS to fully utilize the high-intensity nm-beams.