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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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Insights into Solid-To-Solid Transformation of MOF Amorphous Phases
Yuri A Mezenov1, Stephanie Bruyere2, Andrei Krasilin3
1School of Physics and Engineering, ITMO University, St. Petersburg 197101 Russia.
Inorganic Chemistry
|August 24, 2022
Summary
Electron-induced amorphization of metal-organic frameworks (MOFs) was studied in real-time. The metal cluster topology dictates the transformation rate and resulting amorphous nanomaterial properties, enabling new optical material design.
Area of Science:
- Materials Science
- Nanotechnology
- Solid-State Chemistry
Background:
- Metal-organic frameworks (MOFs) are crystalline materials convertible to amorphous phases with diverse properties.
- Controlling MOF structural transformations in real-time remains a significant challenge.
Purpose of the Study:
- To investigate the real-time, electron-induced amorphization of MOF single crystals.
- To understand how parent MOF structure influences the resulting amorphous nanomaterials.
- To establish structure-property relationships for designing novel amorphous MOF-based optical materials.
Main Methods:
- In situ high-resolution transmission electron microscopy (HRTEM) with 0.01 s time resolution.
- Comparative study of various M-BTC MOFs (M = Fe, Co, Ni, Cu; BTC = 1,3,5-benzenetricarboxylate).
- Confocal Raman and photoluminescence spectroscopies for chemical and optical analysis.
Main Results:
- Electron-induced amorphization dynamics were captured in real-time.
- The topology of the metal cluster in parent MOFs controls the amorphization rate and the chemistry of the resulting amorphous phase.
- Intact BTC ligands and metal/metal oxide nanoparticles were observed in the amorphous phases.
- Spectroscopic and imaging analyses confirmed ligand integrity, coordination bond breaking, and solid-to-solid transformation dynamics.
Conclusions:
- A direct relationship between initial MOF structure and resulting amorphous phase properties was established.
- The stability and photoluminescence of the amorphous phases were characterized over time.
- This study provides a framework for designing amorphous MOF-based optical nanomaterials with tailored properties.
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