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We report a quartz crystal microbalance study of the nanodynamical properties of tricresylphosphate (TCP) reaction films formed on high purity Fe, Cr, Fe oxide, and Cr oxide surfaces at elevated temperatures. The data reveal trace levels of interfacial slippage, potentially in conjunction with viscoelastic effects, for reaction films characterized by very low macroscopic friction coefficients. In contrast, rigidly attached TCP reaction films are observed in systems characterized by high macroscopic friction coefficients.

We have observed that when mobile adsorbed films of benzene, tricresyl phosphate, and tertiary-butyl phenyl phosphate are present on the surface electrode of a quartz crystal microbalance (QCM), oscillation of the QCM produces clearer scanning tunneling microscope (STM) images of the electrode surface. This is in contrast to an immobile overlayer of iodobenzene, where oscillation of the QCM does not affect image quality. This observation is attributed to a "windshield wiper effect", where at MHz frequencies the tip motion maintains a region of the surface where the absorbate concentration is reduced, which leads to a clearer image. A straightforward model is presented that supports this conclusion and that provides guidelines for effective lubrication of contacts operating at MHz frequencies.

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We have investigated the changes in interfacial friction of toluene on mica and Ag(111) both in the presence and in the absence of interfacial C 60 layers employing atomic force microscope (AFM) and quartz crystal microbalance (QCM) techniques. The lateral force measurements fail to detect C 60 at the toluene/mica interface, presumably because the C 60 is dislodged by the slowmoving probe tip. In contrast, QCM measurements of interfacial friction and slippage for toluene/Ag(111) are sensitive to the presence of interfacial C 60. We see the friction double when C 60 is present. The results are discussed in the light of the full-slip boundary condition which had been previously reported for surface forces apparatus (SFA) measurements on toluene/mica in the presence and absence of interfacial C 60 .

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