Some galvanomagnetic and thermomagnetic effects in n+type indium antimonide

Abstract

D.C. measurements were made of the magnetoresistance and magneto-thermo-electric power to study the Gurevich-Firsov oscillations in n-InSb. The G-F oscillations are quasi-periodic in the reciprocal field. The transverse Nernst-Ettinghausen effect was measured at 91.5 K but the G-F oscillations were obscured by inhomogeneities. The separation of the physical transverse N-E effect from the effect due to inhomogeneities is considered. Longitudinal and transverse resistivity and Hall coefficient were measured as a function of the electric field at 2.4, 3.1,3.7, 4.2 K up to 40 KG to study the magnetic freeze out and impact ionisation effects. A comparative study shows that the freeze out effects and the avalanche ionisation are more readily understood from the measurements of longitudinal resistivity rather than from the measurements of transverse resistivity and Hall effect. Assuming that the electrons in the conduction band only contribute to the conductivity the donor ionisation energies as a function of the magnetic field are calculated and compared with the YKA theory. The breakdown field is found to be directly proportional to the calculated donor ionisation energy at 4.2 K.