The measured R-B curves under pulsed high magnetic field at 300 K when (a) I<Ith and (b) I>Ith.
Background
In non-magnetic semiconductor materials, unsaturated magnetoresistance effect has attracted lots of attention due to its physical interests and potential applications in electronic devices, such as magnetic sensors and non-volatile reconfigurable logic devices. Amongst these non-magnetic materials, considering the high compatibility with modern electronic industry, non-magnetic semiconductor will be a better candidate material. Under pulsed high magnetic field, the charge particles will be more intensely affected by extremely strong Lorentz force. Then how will the magnetoresistance characteristics of these non-magnetic semiconductor materials and their electronic devices evolve? Previous researches on the magnetoresistance behaviors under pulsed high magnetic field are mainly concentrated on the intrinsic ohmic transport region. The magnetoresistance behaviors in non-ohmic regions are still unclear. This is unfavourable for the application of non-magnetic semiconductor based electronic devices in high magnetic field environment and the evaluation of the stability and reliability of these electronic devices under strong magnetic pulses.
What we discover?
In this paper, we investigate the transport properties of non-magnetic Ag/p-Ge:Ga/Ag devices under 45 T pulsed high magnetic field at 300 K. It is found that in ohmic conduction region (I< 5 mA) where the single dominant carrier is hole, themagnetoresistancevalues 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 transportis dominated by bipolar (electrons and holes), a magnetoresistance retraction has been obviously observed under pulsed high magnetic field. In addition, combining the Hall measurement results and calculation of Hall effect withbipolar-driven transport model, the mechanism of the magnetoresistance retraction is analyzed, in which the magnetoresistance retraction may be related to the strong regulation of electron-to-hole density ratio by pulsed high magnetic field.
Why is this important?
Themagnetoresistanceproperties of the electronic devices with bipolar transport are excellent, which makes them have great application prospects in non-magnetic semiconductor electronic industries, especially for those compatible with existing semiconductor technology, such as germanium-based semiconductor devices. Through this research results, it is found that themagnetoresistanceof such devices may retract under the pulsed highmagnetic field. Therefore, research on the electrical transport properties of these devices under a pulsed highmagnetic fieldwill be expected to evaluate the stability and reliability of these electronic devices under strong magnetic pulses.
Why did we need WHMFC?
Using the outstanding characteristics of ultra-high magnetic field strength and ultra-fast sweeping rate of the pulsed high magnetic field, the stronger modulation of electrons and holes in semiconductor devices is realized, and a novel physical phenomenon may be observed. In this work, the magnetoresistance and Hall behaviors up to about 45 T were measured by applying the electrical transport platform at the Wuhan National High Magnetic Field Center (WHMFC).
Who did the research?
Xiong He1, Zhengcai Xia1,2,*, Haoyu Niu1,2, Zhuo Zeng1,2
1Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
2School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
Acknowledgments
This work was supported in part by the National Natural Science Foundation of China (Grant Nos. 11674115 and 51861135104) and National Key R&D Program of China (Grant No. 2016YFA0401003).
Link
https://doi.org/10.1016/j.jmst.2021.08.040
