Journal article
Probing the structure of vanadium tetracyanoethylene using electron energy-loss spectroscopy
APL materials, Vol.10(8), pp.81102-081102-9
08/01/2022
DOI: 10.1063/5.0087997
Abstract
The molecule-based ferrimagnetic semiconductor vanadium tetracyanoethylene (V[TCNE](x), x approximate to 2) has garnered interest from the quantum information community due to its excellent coherent magnonic properties and ease of on-chip integration. Despite these attractive properties, a detailed understanding of the electronic structure and mechanism for long-range magnetic ordering have remained elusive due to a lack of detailed atomic and electronic structural information. Previous studies via x-ray absorption near edge spectroscopy and the extended x-ray absorption fine structure have led to various proposed structures, and in general, V[TCNE](x) is believed to be a three-dimensional network of octahedrally coordinated V2+, each bonded to six TCNE molecules. Here, we elucidate the electronic structure, structural ordering, and degradation pathways of V[TCNE](x) films by correlating calculations of density functional theory (DFT) with scanning transmission electron microscopy and electron energy-loss spectroscopy (EELS) of V[TCNE](x) films. Low-loss EELS measurements reveal a bandgap and an excited state structure that agree quantitatively with DFT modeling, including an energy splitting between apical and equatorial TCNE ligands within the structure, providing experimental results directly backed by theoretical descriptions of the electronic structure driving the robust magnetic ordering in these films. Core-loss EELS confirms the presence of octahedrally coordinated V+2 atoms. Upon oxidation, changes in the C1s-pi* peak indicate that C=C of TCNE is preferentially attacked. Furthermore, we identify a relaxation of the structural ordering as the films age. These results lay the foundation for a more comprehensive and fundamental understanding of magnetic ordering and dynamics in these classes of metal-ligand compounds.
Details
- Title: Subtitle
- Probing the structure of vanadium tetracyanoethylene using electron energy-loss spectroscopy
- Creators
- Amanda H. Trout - The Ohio State UniversitySeth W. Kurfman - The Ohio State UniversityYueguang Shi - University of IowaMichael Chilcote - The Ohio State UniversityMichael E. Flatte - University of IowaEzekiel Johnston-Halperin - The Ohio State UniversityDavid W. McComb - The Ohio State University
- Resource Type
- Journal article
- Publication Details
- APL materials, Vol.10(8), pp.81102-081102-9
- DOI
- 10.1063/5.0087997
- ISSN
- 2166-532X
- eISSN
- 2166-532X
- Publisher
- AIP Publishing
- Number of pages
- 9
- Grant note
- DOI: 10.13039/100000001, name: National Science Foundation, award: DMR-1808704, DMR-2011876, DMR-1420451, DMR-1808742
- Language
- English
- Date published
- 08/01/2022
- Academic Unit
- Electrical and Computer Engineering; Physics and Astronomy
- Record Identifier
- 9984428830702771
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