  We have developed an experimental system to simultaneously observe surface
structure, morphology, composition, chemical state, and chemical activity for
samples in gas phase environments. This is accomplished by simultaneously
measuring X-ray photoelectron spectroscopy (XPS) and grazing incidence X-ray
scattering (GIXS) in gas pressures as high as the multi-Torr regime, while also
recording mass spectrometry. Scattering patterns reflect near-surface sample
structures from the nano- to the meso-scale. The grazing incidence geometry
provides tunable depth sensitivity while scattered X-rays are detected across a
broad range of angles using a newly designed pivoting-UHV-manipulator for
detector positioning. At the same time, XPS and mass spectrometry can be
measured, all from the same sample spot and in ambient conditions. To
demonstrate the capabilities of this system, we measured the chemical state,
composition, and structure of Ag-behenate on a Si(001) wafer in vacuum and in
O$_2$ atmosphere at various temperatures. These simultaneous structural,
chemical, and gas phase product probes enable detailed insights into the
interplay between structure and chemical state for samples in gas phase
environments. The compact size of our pivoting-UHV-manipulator makes it
possible to retrofit this technique into existing spectroscopic instruments
installed at synchrotron beamlines. Because many synchrotron facilities are
planning or undergoing upgrades to diffraction limited storage rings with
transversely coherent beams, a newly emerging set of coherent X-ray scattering
experiments can greatly benefit from the concepts we present here.
