A New Type of Oscillations in Germanium under the Magnetic Field

Abstract

A negative resistance characteristics is observed in compensated germanium at liquid helium temperature. The sustaining field strength is changed by the transverse magnetic field. A new type of oscillation phenomenon is observed at the sustaining region when a magnetic field over a critical value is applied. Samples were prepared from highly compensated germanium single crystal and shaped in a form of rectangular bars. The oscillation frequency, w, is dependent on the crystal orientation with respect to the magnetic field and the current directions. The empirical formula relating the oscillation frequency to the cross section of a sample, L2, a magnetic field strength, H, and a majority impurity concentration, Nm, is given by ω∝\\frac{N{_{m}}^{1/3}H}{L^{2}}∼\\frac{H}{r_{m}L^{2}} where rm is the mean separation of a majority impurity atoms.