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Nanoscale Tantalum layer impacting magnetic properties of tunnel junction-based molecular devices

Published online by Cambridge University Press:  23 July 2018

Pawan Tyagi*
Affiliation:
Mechanical Engineering, University of the District of Columbia, Washington DC-20008, USA Chemical and Materials Engineering, University of Kentucky, Lexington, KY-40566, USA
Tobias Goulet
Affiliation:
Mechanical Engineering, University of the District of Columbia, Washington DC-20008, USA
*
Address all correspondence to Pawan Tyagi at [email protected]
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Abstract

Magnetic tunnel junction can produce highly configurable molecular spintronics devices. This paper highlights a rather subtle attribute of magnetic tunnel junction fabrication that can lead to the very pronounced impact on magnetic properties of molecular spintronics device. We conducted magnetic studies to observe the effect of depositing ~5 nm Tantalum (Ta) on the top of a magnetic tunnel junction. We investigated the effect of Ta by using characterization techniques like ferromagnetic resonance, magnetometry, and polarized neutron reflectometry. Bridging paramagnetic molecules between the two ferromagnetic electrodes of magnetic tunnel junctions with and without Ta top layer produced the very different magnetic response.

Type
Research Letters
Copyright
Copyright © Materials Research Society 2018 

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References

1.Miao, G.X., Munzenberg, M., and Moodera, J.S.: Tunneling path toward spintronics. Rep. Prog. Phys. 74, 036501 (2011).Google Scholar
2.Tyagi, P.: Multilayer edge molecular electronics devices: a review. J. Mater. Chem. 21, 4733 (2011).Google Scholar
3.Tyagi, P., Friebe, E., and Baker, C.: Advantages of prefabricated tunnel junction based molecular spintronics devices. NANO 10, 1530002 (2015).Google Scholar
4.Yuasa, S. and Djayaprawira, D.: Giant tunnel magnetoresistance in magnetic tunnel junctions with a crystalline MgO (0 0 1) barrier. J. Phys. D: App. Phys. 40, R337 (2007).Google Scholar
5.Kezilebieke, S., Ali, M., Shadeke, B., and Gunnella, R.: Magnetic properties of ultrathin Ni81Fe19 films with Ta and Ru capping layers. J. Phy.-Cond. Mat. 25, 476003 (2013).Google Scholar
6.Kowalewski, M., Butler, W.H., Moghadam, N., Stocks, G.M., Schulthess, T.C., Song, K.J., Thompson, J.R., Arrott, A.S., Zhu, T., Drewes, J., Katti, R.R., McClure, M.T., and Escorcia, O.: The effect of Ta on the magnetic thickness of permalloy (Ni81Fe19) films. J. Appl. Phys. 87, 5732 (2000).Google Scholar
7.Baberschke, K.: Magnetic anisotropy energy and interlayer exchange coupling in ultrathin ferromagnets: Experiment versus theory. Philos. Mag. 88, 2643 (2008).Google Scholar
8.Geshev, J., Pereira, L.G., and Schmidt, J.E.: Dependence of the ferromagnetic resonance modes on the coupling strength in exchange-coupled trilayer structures. Physica B-Condens. Matter 320, 169 (2002).Google Scholar
9.Linder, J. and Baberschke, K.: Ferromagnetic resonance in coupled ultrathin films. J. Phys. -Condens. Matter 15, S465 (2003).Google Scholar
10.Demokritov, S.O.: Biquadratic interlayer coupling in layered magnetic systems. J. Phys. D-Appl. Phys. 31, 925 (1998).Google Scholar
11.Tyagi, P., D'Angelo, C., and Baker, C.: Monte Carlo and experimental magnetic studies of molecular spintronics devices. NANO 10, 1550056 (2015).Google Scholar
12.Li, D.F., Parkin, S., Wang, G.B., Yee, G.T., Clerac, R., Wernsdorfer, W., and Holmes, S.M.: An S = 6 cyanide-bridged octanuclear (Fe4Ni4II)-Ni-III complex that exhibits slow relaxation of the magnetization. J. Am. Chem. Soc. 128, 4214 (2006).Google Scholar
13.Tyagi, P., Baker, C., and D'Angelo, C.: Paramagnetic molecule induced strong antiferromagnetic exchange coupling on a magnetic tunnel junction based molecular spintronics device. Nanotechnology 26, 305602 (2015).Google Scholar
14.Tyagi, P., Li, D.F., Holmes, S.M., and Hinds, B.J.: Molecular electrodes at the exposed edge of metal/insulator/metal trilayer structures. J. Am. Chem. Soc. 129, 4929 (2007).Google Scholar