Electrical control of memristance and magnetoresistance in oxide magnetic tunnel junctions

Abstract
Electric-field control of magnetic and transport properties of magnetic tunnel junctions has promising applications in spintronics. Here, we experimentally demonstrate a reversible electrical manipulation of memristance, magnetoresistance, and exchange bias in Co/CoO–ZnO/Co magnetic tunnel junctions, which enables the realization of four nonvolatile resistance states. Moreover, greatly enhanced tunneling magnetoresistance of 68% was observed due to the enhanced spin polarization of the bottom Co/CoO interface. The ab initio calculations further indicate that the spin polarization of the Co/CoO interface is as high as 73% near the Fermi level and plenty of oxygen vacancies can induce metal–insulator transition of the CoO1−v layer. Thus, the electrical manipulation mechanism on the memristance, magnetoresistance and exchange bias can be attributed to the electric-field-driven migration of oxygen ions/vacancies between very thin CoO and ZnO layers.

Citation
Zhang K, Cao Y, Fang Y, Li Q, Zhang J, et al. (2015) Electrical control of memristance and magnetoresistance in oxide magnetic tunnel junctions. Nanoscale 7: 6334–6339. Available: http://dx.doi.org/10.1039/c5nr00522a.

Acknowledgements
Y.W. Fang appreciates useful discussions with U.D. Wdowik of Pedagogical University, S. Grytsyuk from KAUST and Prof. Marie-Liesse Doublet from CNRS. This work was supported by the key program of NSFC no. 11434006, the NBRP of China no. 2013CB922303 and 2014CB921104, the NSF for Distinguished Young Scholars of China (no. 51125004), 111 project no. B13029, and NSFC no. 11374187 and 61125403.

Publisher
Royal Society of Chemistry (RSC)

Journal
Nanoscale

DOI
10.1039/c5nr00522a

PubMed ID
25785667

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