An Electrodeposition Process Followed by X-ray Microscopy

Abstract

Time-dependent X-ray microscopy has been applied for the first time to follow an electrodeposition process: that of copper on a glassy carbon electrode. From a series of X-ray microradiographs taken every 20 s it is possible not only to measure directly the increasing thickness of the coating but also to evaluate the copper sulfate concentration profile in the electrolyte at the corresponding instants of acquisition. When the electrodeposition conditions lead to ramified growth close to coating/electrolyte interface, local variations of the ionic concentration are observed as a function of time and of coordinates. The lateral resolution is in the 10−20 μm range and relative concentration changes of few percent are easily detected.

X-ray radiography applied to an investigation of thermal diffusion

“…The radiographs have been subjected to a logarithmic compression which gives the absorption map (i.e. the space distribution of µt values, for each solution) using equation (2). The images of the four solutions presented in figures 3(a)-(d ) come from the subtraction pixel by pixel of the absorption map of the empty cell from the absorption map of the cell filled with the KI solution.…”

“…In the last ten years, x-ray microscopy implemented in a scanning electron microscope has allowed one to follow and quantify, on the one hand, the diffusion of species in liquids as a function of time during chemical reactions [1,2] and, on the other hand, intercalation fronts of sulphuric acid into highly oriented pyrographite (HOPG), thus giving direct access to mobility and diffusion coefficient [3]. The evolution of the concentration profiles of two species during a corrosion process was also easy to deduce with this technique [4,5].…”