An Electropainting Method For Coating Stm Tips For Electrochemical Measurements

This insulation method for EC-STM tips consists of two steps. In the first step, a film is evenly deposited on the tip surface by dipping the tip in an electrophoretic paint and applying a voltage between the tip and a platinum electrode. The film is hardened in the second step by heating the coated tip. In contrast to other coating methods for EC-STM tips, the electropainting method is convenient and quick. We have tested the method for commercially available etched and cut Pt/Ir tips. The coated tips were characterized by voltammetric methods, scanning electron microscopy and by in situ STM imaging of various samples. Our results show for both tip types that there is a very small uncoated area at the very end of the tip and that imaging with atomic resolution and imaging of dynamical electrochemical processes is possible. Coating with electrophoretic paint proved to be a reliable and effective insulation method for EC-STM tips.