Magnetoresistance retraction behaviour of Ag/p‐Ge:Ga/Ag device under pulsed high magnetic field

Abstract

In non-magnetic semiconductor materials, unsaturated magnetoresistance (MR) effect has attracted lots of attention due to its physical interests and potential applications in electronic devices. Under the extremely high magnetic field, the stability and reliability of MR effects based on the non-ohmic transport has been rarely researched. In this paper, the transport properties of non-magnetic Ag/p-Ge:Ga/Ag devices under 45 T pulsed high magnetic field at 300 K are investigated. It is found that in ohmic conduction region ( I <5 mA) where the single dominant carrier is hole, the MR values increase with increasing the applied magnetic field, presenting a conventional unsaturated behavior. In the two non-ohmic regions (5 mA≤ I ≤ 100 mA) where the transport is dominated by bipolar (electrons and holes), a MR retraction has been obviously observed under pulsed high magnetic field. Combining the Hall measurement results and calculation of Hall effect with bipolar-driven transport model, the mechanism of the MR retraction is analysed, in which the MR retraction may be related to the strong regulation of electron-to-hole density ratio by pulsed high magnetic field. This work provides a reference for evaluating the stability and reliability of the properties of non-magnetic semiconductor based MR devices under the interference of strong magnetic pulses.