Current Instability in n-and p-Type InSb under Crossed Electric and Magnetic Fields

Publisher Website
Google Scholar
Abstract
The current density and the Hall coefficient of n-and p-type InSb were measured as a function of electric field, E, up to 1000 volt/cm in a transverse magnetic field, H, from 1000 to 6000 gauss at 77°K. In n-InSb, for H>2000 gauss, incoherent current oscillations with frequency of 20∼50 Mc/sec set in at E≃100 volt/cm, which is smaller than the intrinsic “breakdown” field, simultaneously with the saturation of the “Hall” drift velocity, while, for HE≃200∼300 volt/cm (the “breakdown,, field). As the magnetic field is increased, the threshold electric field of oscillations decreases, at first, in proportion to the reciprocal of H, reaches a minimum at H≃3500 gauss and increases with further increase of H. There seems to be optimum values of E and H for oscillations. Some discussions were made on a possibility of the instability of weakly ionized plasma due to the presence of a density gradient parallel to the current direction. In p-InSb, the threshold electric field of oscillations is nearly independent of magnetic field up to 6000 gauss and it is likely that the acoustic instability is the cause of oscillations.

This publication has 14 references indexed in Scilit: