Frequency Dependence of Ultrasonic Attenuation in Germanium

Abstract

The attenuation of compressional waves traveling in the [100] direction in germanium has been measured in the frequency range from 5 to 300 Mc/sec. Below 20 Mc/sec, the loss was found to be mostly due to diffraction. The remaining attenuation can be described by an expression of the form α=Kfⁿ, where α is the attenuation, f the frequency, n a constant near but somewhat less than two, and K a constant. The attenuation is attributed to the damped forced oscillation of dislocation segments. The value of the damping constant found from the data (about 1.1×10⁻⁴ g‐sec⁻¹‐cm⁻¹) is in agreement with the estimate of Leibfried and Nabarro.