Aqueous iron (III) oxide nanoparticles were irradiated with pure self-amplified spontaneous emission (SASE) X-ray free-electron laser (XFEL) pulses tuned to the energy around Fe K-edge ionization threshold. For each XFEL shot, incident pulse spectrum and Kβ measured synchronously dedicated spectrometers processed through a reconstruction algorithm allowing for determination of resonant spectros...

The chemical and electronic structures of 15 different sulfates are studied using S L2,3 soft X-ray emission spectroscopy (XES). Sulfur XES spectra distinctively from those other sulfur compounds, which makes a powerful technique for sulfate detection. Furthermore, subtle but distinct differences between the with cations observed, allow further differentiation specific compound. Most prominentl...