New pulse measurements of the high-field conductivity of $n$-type germanium at room temperature have been performed. Contrary to previous measurements, the conductivity is anisotropic above the Ohmic field range. The highest current for a given field is found along the <100> crystallographic axes; the <110> current is as much as 9% lower, and the <111> current 14% lower than the <100> current. The maximum anisotropy is found at a field of 3 kV/cm. No region of constant drift velocity is found; current increases with field up to 30 kV/cm, the highest field applied.

• Received 7 October 1968

DOI:https://doi.org/10.1103/PhysRev.178.1364