Q‐factor study of nanomechanical system “metal tip – carbon nanowhisker” at low and ambient pressure

Nanomechanical oscillators based on amorphous carbon whiskers, localized on the top of tungsten tip were fabricated and investigated. The whiskers were grown in the scanning electron microscope chamber using focused electron beam technique. Oscillation trajectories and amplitude-frequency characteristic of the oscillator were visualized at low and ambient pressure using a scanning electron microscope and a confocal laser-scanning microscope, respectively. We experimentally show that at ambient pressure, the resonant frequency decreases significantly but the Q-factor of the oscillator unexpectedly increases with respect to experimental data acquired at low pressure. The explanation was provided taking into account the role of thin water layer absorbed on the whisker from atmosphere. The model of the coupled oscillators is considered.