Kolosov, Oleg and Yamanaka, K (1993) Nonlinear Detection of Ultrasonic Vibrations in an Atomic Force Microscope. Japanese Journal of Applied Physics, 32 (8A). L1095-L1098. ISSN 0021-4922
Full text not available from this repository.Abstract
A new method is proposed to detect ultrasonic vibration of the samples in the Atomic Force Microscope (AFM) using nonlinearity in the tip-sample interaction force curve F(z). Small amplitude ultrasonic vibration less than 0.2 nm is detected as an average displacement of a cantilever. This Ultrasonic Force Mode (UFM) of operation is advantageous in detecting ultrasonic vibration with frequencies up to the GHz range, using an AFM cantilever with a resonant frequency below 100 kHz. It was found that a strong repulsive force is acting after an ultrasonic amplitude threshold of the is crossed, with the amplitude of this threshold depending upon the average force applied to the tip.