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Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
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Heterometallic Gd-Dy Formate Frameworks for Enhanced Magnetocaloric Properties
Suhwan Kim1, Raeesh Muhammad2, Kwanghyo Son3
1Future Convergence Technology Research Institute, Gyeongsang National University, Jinju 52725, Republic of Korea.
Inorganic Chemistry
|February 9, 2023
Summary
Lanthanide-based metal-organic frameworks (MOFs) show promise for magnetic cooling. Introducing dysprosium (Dy3+) ions to gadolinium (Gd3+) MOFs extends their operating temperature beyond cryogenic conditions.
Area of Science:
- Materials Science
- Magnetism
- Chemical Engineering
Background:
- Lanthanide-based metal-organic frameworks (MOFs) are investigated as advanced magnetic refrigerants for cryogenic applications.
- Gadolinium (Gd3+)-based MOFs exhibit excellent magnetic refrigerant properties due to large spin ground states, but their application is limited to cryogenic temperatures.
- The ligand material does not significantly influence Gd3+-based MOFs due to their large spin-only magnetic moment.
Purpose of the Study:
- To investigate the magnetic properties and magnetocaloric effect (MCE) of heterogenized MOFs synthesized from Gd3+ and Dy3+ ions.
- To explore the impact of varying molar compositions of Gd3+ and Dy3+ with formate ligands on MCE.
- To determine the potential of Dy3+ incorporation for extending the operating temperature range of magnetic cooling materials.
Main Methods:
- Synthesis of heterogenized MOFs with the general formula GdxDy1-x(HCOO)3, where 0 ≤ x ≤ 1.
- Measurement of magnetic properties and magnetocaloric effect (MCE) for various Gd3+/Dy3+ molar ratios.
- Analysis of the isothermal magnetic entropy change (ΔSm) as a function of temperature and applied magnetic field.
Main Results:
- The isothermal magnetic entropy change (ΔSm) increased with increasing Gd3+ fraction in the heterogenized MOFs.
- Increasing Dy3+ content shifted the maximum ΔSm peak to higher temperatures while maintaining a high ΔSm value (22.35 J·kg-1 K-1 at 7 K and 7 T).
- MOF samples with 75% or more Dy3+ content demonstrated a longer-lasting ΔSm operating temperature.
Conclusions:
- The incorporation of Dy3+ ions into lanthanide-based MOFs effectively enhances their magnetocaloric properties.
- This strategy allows for the extension of magnetic cooling material operating temperatures beyond traditional cryogenic limits.
- Heterogenized Gd3+-Dy3+ formate MOFs present a viable pathway for developing advanced magnetic refrigeration technologies.
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