Abstract
The ambient-pressure endstation and branchline of the Versatile Soft X-ray (VerSoX) beamline B07 at Diamond Light Source serves a very diverse user community studying heterogeneous catalysts, pharmaceuticals and biomaterials under realistic conditions, liquids and ices, and novel electronic, photonic and battery materials. The instrument facilitates studies of the near-surface chemical composition, electronic and geometric structure of a variety of samples using X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy in the photon energy range from 170 eV to 2800 eV. The beamline provides a resolving power hν/Δ(hν) > 5000 at a photon flux > 1010 photons s-1 over most of its energy range. By operating the optical elements in a low-pressure oxygen atmosphere, carbon contamination can be almost completely eliminated, which makes the beamline particularly suitable for carbon K-edge NEXAFS. The endstation can be operated at pressures up to 100 mbar, whereby XPS can be routinely performed up to 30 mbar. A selection of typical data demonstrates the capability of the instrument to analyse details of the surface composition of solid samples under ambient-pressure conditions using XPS and NEXAFS. In addition, it offers a convenient way of analysing the gas phase through X-ray absorption spectroscopy. Short XPS spectra can be measured at a time scale of tens of seconds. The shortest data acquisition times for NEXAFS are around 0.5 s per data point.
Highlights
Over the last decade, there has been growing demand for a better understanding of the near-surface regions of a variety of samples in non-vacuum environments (Salmeron & Schlogl, 2008; Starr et al, 2013), including heterogeneous catalysts under reaction conditions, pharmaceuticals and biomaterials in aqueous environments, electronic and photonic devices under realistic humidity conditions, and environmental studies on liquids and ices
The ambient-pressure endstation of the new VerSoX (Versatile Soft X-ray) beamline B07 at Diamond Light Source is dedicated to X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) experiments under near-ambient pressure conditions
They were measured in March 2019 using the total electron yield (TEY) signal of He gas in order to avoid features from carbon contamination on the photodiode
Summary
There has been growing demand for a better understanding of the near-surface regions of a variety of samples in non-vacuum environments (Salmeron & Schlogl, 2008; Starr et al, 2013), including heterogeneous catalysts under reaction conditions, pharmaceuticals and biomaterials in aqueous environments, electronic and photonic devices under realistic humidity conditions, and environmental studies on liquids and ices All these areas of science have a common interest in the chemical nature and composition of the nearsurface atomic layers. The ambient-pressure endstation of the new VerSoX (Versatile Soft X-ray) beamline B07 at Diamond Light Source is dedicated to XPS and NEXAFS experiments under near-ambient pressure conditions (up to 100 mbar) It enables studying the surface composition of heterogeneous catalysts under working conditions (as opposed to conventional ex situ characterization), characterization of biological and pharmaceutical samples under equilibrium water-vapour conditions at room temperature (32 mbar), and direct spectroscopy of surfaces of liquids. In this paper we present the general considerations which guided the specifications and design of the beamline and endstation, their performance, and a selection of data demonstrating the capabilities of the instrument in terms of energy resolution and ambient-pressure environments
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
