MECHANICAL FEATURES OF THE SPM MICROPROBE AND NANOSCALE MASS DETECTOR

摘要

The problem of loss of atomic resolution in SPM experiments with a modulating technique on the SPM microprobe is considered. The possibility of a mass detector is also analyzed, where the nanometer size SPM microtip plays the role of detecting mechanical oscillator. The limits of the device's sensitivity are considered. For these purposes a mechanical model of enforced oscillations for the SPM microprobe with a circular and variable size cross section is considered. An analytical solution of the spectral problem for the exponential profile of the SPM microprobe has been found to be in agreement with the results of computer simulation. Positioning for the SPM at real working frequencies causes microprobe oscillations of the order of magnitude of approximate to 5 Angstrom and may lead to the loss of atomic resolution. The sensitivity of the nanoscale mass detector is delta M approximate to 10(-24) g for normal pressure, room temperature and eigenmode frequency of 10 GHz. [References: 14]