Raman Spectroscopy and Photoluminescence of Vanadium Tetracyanoethylene

ORAL

Abstract

Vanadium tetracyanoethylene (V[TCNE]x≈2) is an organic-based ferrimagnet, with an ultra-low magnetic damping rate, comparable to yttrium iron garnet (YIG). Its mild growth conditions allow integration with a wide variety of processes. V[TCNE]x≈2 is air sensitive, but its lifetime in ambient conditions can be extended to several weeks by encapsulating it with epoxy while preserving its low magnetic damping. However, its ageing mechanism is not well studied. Here we use confocal microscopy, microfocused Raman spectroscopy, and ferromagnetic resonance to study V[TCNE]x≈2 and its ageing process. We identify Raman peaks in agreement with density functional theory calculations. These calculations, using the VASP code, help distinguish the frequency ranges for contributions from CN, CC and VN bonds. By comparing optical features with ferromagnetic resonance measurements, we monitor the V[TCNE]x≈2 film as it ages. We find a correlation between a reduction in the effective magnetization 4πMs-Hk and changes in Raman intensity as well as increases in the photoluminescence of the material. These results enable optical measurements that locally probe V[TCNE]x≈2 film quality.

*This work is supported by DOE award #DE-SC0019250.

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Presenters

  • Hil Cheung

    • School of Applied and Engineering Physics, Cornell University

Authors

  • Hil Cheung

    • School of Applied and Engineering Physics, Cornell University

  • Michael Chilcote

    • School of Applied and Engineering Physics, Cornell University

  • Donley S Cormode

    • Department of Physics, The Ohio State University

  • Huma Yusuf

    • Department of Physics, The Ohio State University

  • Yueguang Shi

    • Department of Physics, University of Iowa
    • Department of Physics and Astronomy, University of Iowa
    • Department of Physics and Astronomy, The University of Iowa

  • Ezekiel Johnston-Halperin

    • Department of Physics, Ohio State Univ - Columbus
    • Department of Physics, The Ohio State University

  • Michael Flatté

    • Department of Physics and Astronomy, The University of Iowa
    • University of Iowa
    • Department of Physics, University of Iowa
    • Physics and Astronomy, Univ of Iowa
    • Department of Physics and Astronomy, University of Iowa, Department of Applied Physics, Eindhoven University of Technology
    • Department of Physics, University of Iowa; Department of Applied Physics, Eindhoven University of Technology
    • Univ. of Iowa/Eindoven University of Technology
    • Department of Physics and Astronomy, University of Iowa
    • Univ of Iowa

  • Gregory Fuchs

    • Cornell University
    • AEP, Cornell University
    • School of Applied and Engineering Physics, Cornell University