Nonlocal electromagnetic generation of acoustic waves in aluminum films

Publisher Website
Google Scholar
Abstract
The first observation of electromagnetic acoustic-wave generation in deposited metal films at radio frequencies is reported. The electromagnetic-to-acoustic generation efficiency has been determined in absolute measurements from 90 to 400 MHz in aluminum films. Measurements have also been performed in a magnetic field to 50 kG over the frequency range 200-360 MHz. The frequency dependence of the generation efficiency is found to be in good agreement with free-electron theory. However, the magnitude of the generation efficiency is several times larger than the theoretical prediction, in agreement with previous results on bulk samples of aluminum and potassium at lower frequency.