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

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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.

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Acknowledgments

Pawan Tyagi thank Dr. Bruce Hinds and Department of Chemical and Materials engineering at the University of Kentucky for facilitating experimental work on molecular spin-tronics during his Ph.D. OMC was produced by Dr. Stephen Holmes’s group. The preparation of this paper and complementary experiments were in part supported by the National Science Foundation-Research Initiation Award (Contract # HRD-1238802) and Air Force Office of Sponsored Research (Award #FA9550-13-1-0152). We also thank Centre of Nanoscience and Technology, NIST Gaithersburg for allowing the use of microscopy resources. We also acknowledge Dr. Brian Kirby of NIST Center of Neutron Reflectivity for the polarized beam reflectivity study. We also thank the STEM Center at UDC for providing the partial funding. Any opinions, findings, and conclusions expressed in this material are those of the author(s) and do not necessarily reflect the views of any funding agency and corresponding author’s affiliations and collaborators.

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Authors and Affiliations

  1. Mechanical Engineering, University of the District of Columbia, Washington DC, 20008, USA

    Pawan Tyagi

  2. Chemical and Materials Engineering, University of Kentucky, Lexington, KY, 40566, USA

    Pawan Tyagi

  3. Mechanical Engineering, University of the District of Columbia, Washington DC, 20008, USA

    Tobias Goulet

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  1. Pawan Tyagi
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  2. Tobias Goulet
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Correspondence to Pawan Tyagi.

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Tyagi, P., Goulet, T. Nanoscale Tantalum layer impacting magnetic properties of tunnel junction-based molecular devices. MRS Communications 8, 1024–1028 (2018). https://doi.org/10.1557/mrc.2018.132

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  • DOI: https://doi.org/10.1557/mrc.2018.132

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