Nanoacoustics: probing acoustic waves on the nanoscale

Abstract

Two scanning acoustic probe microscopy (SAPM) techniques have been developed for the nanoscale analysis of the interaction of acoustic modes on the surface of a solid. The scanning acoustic force microscope (SAFM) and the scanning acoustic tunneling microscope (SATM) are extensions to the scanning probe microscopy world utilizing the non-linearity of the respective interaction-distance curves in order to detect high-frequency signals, like acoustic waves or electric fields. SAFM and SATM measurements are presented that give an overview of past and present work in this field. With SAPM, acoustic wave properties of arbitrarily polarized surface acoustic wave (SAW) modes can be measured with sub-wavelength resolution and unmatched amplitude sensitivity. SAW dispersion measurements, scattering and diffraction, SAW transducer studies, studies of the crystal anisotropy, as well as atomically resolved images of the oscillating lattice will be discussed.