3. Main SECM applications

3.1 Surface imaging

SECM allows three-dimensional imaging of a sample. To do this, the amperometric probe is moved laterally in the (x, y ) plane, and current variations are measured as a function of its position above the sample. This mode corresponds to the "constant height" regime. The information gathered is then transformed into a three-dimensional image, the z axis of the 3D image corresponding to the current i _T and x and y the coordinates of the points. When the surface has uniform electrochemical reactivity, changes in current i _T as a function of probe position are directly related to variations in the separation between sample and EMU as the probe traverses the surface: surface topography...