Ultrasonic Attenuation in Single-Crystal Aluminum

Abstract

Measurements of the ultrasonic attenuation in single crystals of aluminum as a function of temperature (from 2 to 100\ifmmode^\circ\else\textdegree\fi{}K) and of phonon frequency (from 8 to 24 Mc/sec) are reported. The temperature dependence of the electron mean free path has been determined from these measurements; at temperatures below 25\ifmmode^\circ\else\textdegree\fi{}K, the mean free path shows a ${\mathrm{T}}^{\ensuremath{-}3}$ dependence, and above 25\ifmmode^\circ\else\textdegree\fi{}K, a ${\mathrm{T}}^{\ensuremath{-}5}$ dependence.