High-Field Longitudinal Magnetoresistance of Germanium

The longitudinal magnetoresistance of germanium $N_{100}$, $N_{111}$, $P_{100}$, $P_{111}$, and $P_{211}$ single crystals of 2 ohm cm resistivity has been measured to the point of saturation, by means of transient magnetic fields up to 600 000 gauss. An $N$-type effective mass ratio of 17.2±0.4 has been determined at 300°K. The magnitude and variation with field of the $P$-type magnetoresistances was found to be anomalous.