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Addressing the Challenges of Using Ferromagnetic Electrodes inMolecular Devices

Published online by Cambridge University Press:  24 February 2016

Pawan Tyagi*
Affiliation:
University of the District of Columbia, Department of Mechanical Engineering, 4200 Connecticut Avenue NW Washington DC-20008, USA University of Kentucky, Department of Chemical and Materials Engineering 177 F. Paul Anderson Hall, Lexington KY-40506
Edward Friebe
Affiliation:
University of the District of Columbia, Department of Mechanical Engineering, 4200 Connecticut Avenue NW Washington DC-20008, USA
Collin Baker
Affiliation:
University of the District of Columbia, Department of Mechanical Engineering, 4200 Connecticut Avenue NW Washington DC-20008, USA
*
*Email of corresponding author: [email protected]
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Abstract

Ferromagnetic (FM) electrodes chemically anchored with thiol functionalizedmolecules can yield novel molecular spintronics devices (MSDs). However,significant challenges lie in developing commercially viable MSD fabricationapproach utilizing FM electrodes. A practical MSD fabrication approach shouldconsider FM electrodes’ susceptibility to oxidation, chemicaletching, and stress induced deformations during fabrication and usage. Thispaper will discuss NiFe, an alloy used in the present day memory devices andhigh-temperature engineering applications, as a candidate for FM electrode andfor the fabrication of MSDs. Our spectroscopic reflectance studies show thatNiFe starts oxidizing aggressively beyond ∼90 ⁰C. The NiFesurfaces, aged for several months or heated for several minutes below∼90 ⁰C, were suitable for chemical bonding with thethiol-functionalized molecules. NiFe also demonstrated excellent etchingresistance in widely used dichloromethane solvent for dissolving moleculardevice elements. NiFe also reduced the mechanical stress induced deformities inother FM metals like cobalt. This paper also discusses the successfulutilization of NiFe electrodes in the magnetic tunnel junction based moleculardevice fabrication approach. This research is expected to address the knowledgegap blocking the experimental development of FM based MSDs.

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Articles
Copyright
Copyright © Materials Research Society 2016 

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References

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