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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
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Synchrotron-based Mössbauer spectroscopy characterization of sublimated spin crossover molecules
Alberto Cini1, Lorenzo Poggini, Alexander I Chumakov
1Department of Physics and Astronomy, University of Florence and INSTM Research Unit of Florence, via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy. maria.fittipaldi@unifi.it.
Physical Chemistry Chemical Physics : PCCP
|March 12, 2020
Summary
Spin crossover (SCO) efficiency in iron molecules changes when deposited on gold. This study reveals distortions in the coordination sphere, impacting spin conversion and highlighting synchrotron Mössbauer spectroscopy for nanostructured SCO systems.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Nanotechnology
Background:
- Spin crossover (SCO) molecules exhibit switching between high-spin and low-spin states, crucial for molecular devices.
- The [Fe(bpz)2(phen)] complex is a well-studied SCO material.
- Understanding SCO behavior in thin films is vital for nanoscale applications.
Purpose of the Study:
- To investigate the spin crossover efficiency of [57Fe(bpz)2(phen)] molecules on gold substrates.
- To compare SCO behavior in thin films versus the bulk phase.
- To explore the potential of synchrotron Mössbauer spectroscopy for characterizing nanostructured SCO systems.
Main Methods:
- Synchrotron Mössbauer spectroscopy was employed to study SCO efficiency.
- Spin transitions were induced thermally and via the light-induced excited spin-state trapping (LIESST) effect.
- Analysis of hyperfine parameters in sublimated films was performed.
Main Results:
- SCO efficiency is modified in [57Fe(bpz)2(phen)] molecules deposited on gold compared to the bulk phase.
- A correlation in hyperfine parameter distribution was observed in sublimated films, not seen in bulk.
- Geometrical distortions in the iron atom's first coordination sphere correlate with decreased spin conversion.
Conclusions:
- Substrate interaction significantly alters SCO properties of [57Fe(bpz)2(phen)] molecules.
- Synchrotron Mössbauer spectroscopy is a powerful tool for characterizing nanostructured SCO materials.
- Findings pave the way for developing innovative nanoscale devices utilizing SCO phenomena.
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