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Updated: May 3, 2026

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
Published on: January 21, 2016
Negative magnetoresistance in a vertical single-layer graphene spin valve at room temperature
Arun Kumar Singh1, Jonghwa Eom
1Department of Physics and Graphene Research Institute, Sejong University , Seoul 143-747, Korea.
Abstract:
Single-layer graphene (SLG) is an ideal material for spintronics because of its high charge-carrier mobility, long spin lifetime resulting from the small spin-orbit coupling, and hyperfine interactions of carbon atoms. Here, we report a vertical spin valve with SLG with device configuration Co/SLG/Al2O3/Ni. We observed negative magnetoresistance (-0.4%) for the Co/SLG/Al2O3/Ni junction at room temperature. However, the Co/Al2O3/Ni junction, which is without graphene, shows positive magnetoresistance. The current-voltage (I-V) characteristics of both Co/SLG/Al2O3/Ni and Co/Al2O3/Ni junctions are nonlinear, and this reveals that charge transport occurs by a tunneling mechanism. We have also explained the reason for negative magnetoresistance for the Co/SLG/Al2O3/Ni junction.
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