Simultaneous atomic force microscope and quartz crystal microbalance measurements: Interactions and displacement field of a quartz crystal microbalance

lWe analyze the interaction of two instruments often used in material science analysis. the atomic force microscope (AFM) and the quartz crystal microbalance (QCM), here combined in a single instrument for simultaneous measurement,, oil a single sample. We show. using finite element analysis, that the in-plane displacement of a QCM oscillating ill liquid with a quality factor of 2000 is 2 nm. The out-of-plane displacement is about one tenth of the in-plane displacement. This latter effect, title to the finite size of the electrodes. results in longitudinal acoustic waves launched in the liquid surrounding the QCM. If bounced against an obstacle, in our case the AFM cantilever holder. these longitudinal waves create standing wave patterns which cause frequency fluctuations of the resonator when it is moved, and thus decrease the QCM sensitivity.