Longitudinal magnetoresistance and Hall mobility of n-type germanium at high electric fields

Abstract

The longitudinal magnetoresistance and Hall mobility of 5-Ω·cm n-type germanium have been measured for electric fields applied in the (111) direction up to 4 kV/cm. It has been found that (i) longitudinal magnetoresistance at a particular electric field decreases with an increase in the magnetic field, (ii) for small magnetic fields the longitudinal magnetoresistance decreases with an increase in the electric field, and (iii) the Hall mobility and the ratio of Hall mobility to the conductivity mobility decrease with an increase in the electric field. The experimental value for fields above 1 kV/cm are found to agree with the theoretical values calculated with the assumptions that (i) the scattering is due to the acoustic, optical, and intervalley phonons, (ii) the average energy of the electrons is much larger than that of the optical phonons, (iii) the intervalley phonons affect only the carrier repopulation in the different valleys, and (iv) the value of the optical-phonon deformation potential constant is 0.8×10⁹ eV/cm.