Hysteresis of magnetoresistance in neutron-transmutation-doped Ge in the region of hopping transport over the Coulomb-gap states

The phenomenon of hysteresis of magnetoresistance in neutron-transmutation- doped Ge:Ga in the region of hopping transport over the Coulomb-gap states was observed and studied experimentally. The hysteresis is accompanied by a n abrupt decrease in the resistivity in a magnetic field of about 800 Oe af ter a preliminary magnetization of the samples in the fields exceeding 1 kO e. The relative magnitude of the resistivity jump increases with decreasing temperature. This effect is observed on the insulator side of the metal-in sulator transition, which occurs for a Ga concentration of 1.85 x 10(17) cm (-3). The main special features of the observed phenomenon were studied, an d plausible explanations of this phenomenon are offered. (C) 2000 MAIK "Nau ka / Interperiodica".