Galvanomagnetic properties of grain boundaries in germanium bicrystals from 1.25 to 240°K∗

Abstract

Wide angle grain boundaries of germanium with 20° tilt angles and mean {100}; planes exhibit a p-type conductivity over the temperature range 1.25 to 240°K. The behavior of the conductivity, Hall coefficient and magnetoresistance in the temperature range 1–10°K is found to be the same for n-type, p-type and intrinsic bicrystals. The similarity of results for the three different types of doping indicates that the p-type conductivity is an intrinsic property of the mean {100}; germanium wide angle grain boundary. The number of holes in the space charge region adjacent to the grain boundary and their mobility were found to be 5 × 10 12 per cm 2 and 300 cm 2/V sec respectively. The Hall coefficient is both temperature and magnetic field independent while below 10°K the magnetoresistance exhibits both temperature and magnetic field dependence.