Measurement of amplitude-frequency characteristics of nanomechanical oscillators by visualization of their oscillations in a scanning electron microscope

In this article we propose and test the method of automated measurement of amplitude-frequency characteristics (AFC) of nanomechanical oscillators (NMOS) in the form of carbon nanoviskers (CNV) with a diameter of ~ 100 nm, a length of ~ (1-2) µm and a resonance frequency of ~ (5-10) MHz localized at the top of the W needle is proposed and tested. The frequency response of NMOS was measured by visualizing their forced oscillations in a scanning electron microscope (SEM) and recording the corresponding video file when the frequency of the exciting generator changed. The resulting video sequence is analyzed by machine vision. The result of the processing of SEM images are the graph of frequency response, numerical values of the resonance frequency and quality factor of NMOS. We analyze two methods of measuring the frequency response: scanning alone the line crossing the CNV near its peak and scanning across the frame, including the entire CNV. We suggest the method of the NMO resonance frequency shift `resulting from the deposition of carbon atoms on the surface of the UNV under the action of a focused electron beam in the process of visualization of oscillations in the SEM is estimated. It is shown that the one line scanning during 60 s leads to a decrease in the resonant frequency by ~ 1.5 %, while scanning through the frame during 60 s leads to its increase of ~ 3 %.