Surface and interface characterization of Ru/C/Ru trilayer structure using grazing incidence X‐ray reflectivity and X‐ray fluorescence

Abstract

In 8-to 20-keV photon energy region, ruthenium and carbon thin films are used in multilayer monochromators. In the present study, this material combination is explored for X-ray waveguide applications in hard X-ray region. The structural parameters (thickness of each layer) of Ru/C/Ru waveguide structure are optimized to get maximum intensity enhancement of fundamental mode inside carbon guiding layer. A sample with optimized structural parameters is deposited using ion beam sputtering (IBS) technique and characterized using X-ray reflectivity (XRR) and grazing incidence X-ray fluorescence (GIXRF) techniques. The analysis suggests that the density of bottom Ru layer and carbon guiding layer is close to bulk density ($97% for Ru and $95% for carbon), whereas density of top Ru layer is slightly lower ($93% of bulk density). A $10% of thickness variation in top cladding layer along with marginal change in layer density deteriorate field enhancement in TE 0 mode by more than three times. Effect of thickness and density variation on waveguide (Ru [7 nm]/C [18 nm]/Ru [20 nm]) performance is discussed.

Atomic spectrometry update: review of advances in X-ray fluorescence spectrometry and its special applications

“…The reconstruction also revealed unexpected effects on the nanostructure by, e.g., carbon contamination. The XRR technique was employed 72 in combination with GIXRF techniques for the characterisation of a Ru/C/Ru waveguide. Whereas the bottom layers had densities close to that of the bulk density (within 95% for C and 97% for Ru), the ruthenium top layer had a slightly lower density (within 93% of the bulk density).…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…In a study by Kiranjot et al the use of this material was explored for X-ray waveguide applications in the hard X-ray region. 217 The thickness of each Ru–C–Ru layer was optimized so that maximum intensity enhancement was achieved. The samples were prepared by using ion beam sputtering and were characterized using X-ray reflectivity (XRR) and GIXRF.…”

Study of Ni/AlN/Ni waveguide system for 8.05 keV incident energy

“…Optimum EFI confinement inside a waveguide requires smooth and uniform layers with sharp and well-defined interfaces. Growth conditions and surface-interface properties affect the waveguide gain and efficiency parameters which differ significantly from theoretical predictions [4]. Therefore, a detailed investigation on interfacial properties of a waveguide structure is necessary before utilizing it in actual applications.…”