In-Situ Gracing Incidence X-Ray Diffraction Cell for Electrochemically Formed Thin Films

Abstract

Grazing incidence X-ray diffraction allows surface sensitive measurements of structural and phase properties of thin solid films. For the characterization of layers formed during electrochemical processes ex-situ techniques are usually employed which has the requirement of a stable structure and composition of the formed films even at atmospheric conditions. For cases where this requirement is not met, in-situ techniques have been developed. Existing designs of in-situ electrochemical cells normally have the disadvantage of high absorption of the beam in the setup and/or brittle window materials. The problem of high absorption of the X-ray in the setup is normally compensated by either using very thin electrolyte films or high intensity radiation as is provided by a synchrotron. This work presents a novel solution for a grazing incidence X-ray diffraction setup. Backside-illumination of a thin film working electrode applied on a Mylar® foil by magnetron sputtering as support is used to eliminate the problem of high absorption of the X-ray in the setup. It can be used in a three electrode setup and tackles the common problems of gas evolution, voltage drop and non-constant electrolyte bulk solution in in-situ X-ray setups. The setup is tested on the anodic and cathodic formation of Cu2O on copper as an example for X-ray irradiation from a Lab-scale (not synchrotron) source.Acknowledgement: This work was jointly funded by the Austrian Research Promotion Agency (FFG, Project No. 854247) and the Carinthian Economic Promotion Fund (KWF, contract KWF-1521/28101/40388).