Simultaneous AFM and QCM Measurements -Methodology Validation Using Electrodeposition

We assess the validity and advantages of using a quartz crystal microbalance ~QCM! as the metallic-coated substrate used for atomic force microscopy ~AFM! measurements by studying two well-known electrochemical reactions, silver electrodeposition on gold and copper electrodeposition on gold. We compare the results provided by electrochemistry ~cyclic voltammetry!, QCM frequency, and damping variations as well as AFM topography, and analyze the advantages of combining the three methods in the same instrument. Comparison of the evolution of the frequency of the third and fifth QCM overtones allows identification of the type of interaction between the sensing electrode and its environment: a rigid layer when the frequency shift is proportional to the overtone number, viscous interaction when the frequency shift is proportional to the square root of the overtone number. This identification scheme leads to results confirmed by the QCM damping.