Electrophoretic deposition of siderite thin layers: Influence of electrode potential and deposition time

Siderite thin layers have been obtained by electrophoretic deposition on an inert substrate (gold). Scanning electron microscopy image exhibits a compact and homogeneous film composed of round grains which diameter is about 1-2 µm. The influence of two parameters, namely the electrode potential and the deposition time, on its thickness and its microstructure was investigated. The thickness was shown to be slightly dependent of the electrode potential (1.2 µm for − 0.70 V and 1.7 µm for − 0.95 V after 17 h). The crystallite size, estimated by X-ray diffraction patterns, was about 5 nm, depending on both electrode potential and deposition time. Despite its high sensitivity to oxygen, X-ray photoelectron spectroscopy spectra prove that the siderite surface has been kept out from oxidation. These siderite thin layers could be used as modified electrodes for further interaction studies.