Chemical in‐depth analysis of (Ca/Sr)F ₂ core–shell like nanoparticles by X‐ray photoelectron spectroscopy with tunable excitation energy

The fluorolytic sol–gel synthesis is applied with the intention to obtain two different types of core–shell nanoparticles, namely, SrF2–CaF2 and CaF2–SrF2. In separate fluorination steps for core shell formation, corresponding metal lactates are reacted anhydrous HF in ethylene glycol. Scanning transmission electron microscopy (STEM) dynamic light scattering (DLS) confirm formation particles mean dimensions between 6.4 11.5 nm. overall chemical composition during reaction monitored by quantitative Al Kα excitation X-ray photoelectron spectroscopy (XPS). Here, stoichiometric fluorides (MF2) confirmed, both final particles. Furthermore, an in-depth analysis synchrotron radiation XPS (SR-XPS) tunable energy performed character nanoparticles. Additionally, Ca2p/Sr3d intensity ratio profiles simulated using software Simulation Electron Spectra Surface Analysis (SESSA). principle, like particle morphologies formed but without a sharp interface calcium strontium containing phases. Surprisingly, distribution nanoparticles equal within error experiment. Both comprise SrF2-rich domain CaF2-rich intermixing zone them. Consequently, internal morphology seems be independent from chronology.