Magnetoacoustic Measurements in the Noble Metals at 350 Mc/sec

Further magnetoacoustic measurements on the noble metals are presented for frequencies up to 350 Mc/sec. Plots of the ultrasonic pulse height, $h$, vs the reciprocal of the magnetic field strength, $\frac{1}{H}$, show 20 or more maxima and minima for several orientations in each metal. Fermi surface dimensions are calculated from the periods in $\frac{1}{H}$ of the magnetoacoustic oscillations using the interpretation that the periodicity arises from those portions of the Fermi surface which are extremal in the q×H direction of momentum space; Fermi surface cross sections viewed along the [100], [110], [111], and [112] directions are shown in detail. The results are compared with Fermi surface dimensions given by: (1) other magnetoacoustic effect data, (2) de Haas-van Alphen and anomalous skin-effect data, and (3) recent band theory calculations. Some simple calculations of electron mean free paths and collision relaxation times are given.