Thickness Dependent Oxidation in CrCl ₃ : a Scanning X-ray Photoemission and Kelvin Probe Microscopies Study

 The modifications in the electronic properties induced by the thickness and size of an individual flake of transition-metal halides on different substrates (Si oxide or In-doped tin oxide) are of particular technological interest and even more in the case of the chromium trihalide, whose longer lifetime in ambient conditions is particularly intriguing. By employing synchrotron-based Scanning Photoelectron Microscopy (SPEM) with 0.1 μm resolution and Kelvin Probe Force Microscopy (KPFM), and evaluating the surface modification reaction and surface potential, we established the correlations of the two latter properties with the thickness of flakes, observing a natural tendency to preserve their characteristic when the flakes have significantly less thickness. This preliminary study investigates interfaces made by dry transfer of CrCl ₃ flakes, which induce spin-orbit coupling to systems, otherwise lacking this property.