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Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate
Published on: June 18, 2020
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Energy Migration Upconversion in Manganese(II)-Doped Nanoparticles
Xiyan Li1, Xiaowang Liu1, Daniel M Chevrier2
1Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore).
Angewandte Chemie (International Ed. in English)
|September 12, 2015
Summary
Researchers synthesized core-shell nanoparticles enabling manganese (Mn) upconversion emission at room temperature. This breakthrough utilizes energy transfer in lanthanide tetrafluoride hosts, enhancing light emission for potential applications.
Area of Science:
- Materials Science
- Nanotechnology
- Luminescence
Background:
- Lanthanide-based materials are crucial for optical applications.
- Upconversion luminescence allows conversion of lower energy photons to higher energy photons.
- Controlling energy transfer pathways is key to enhancing luminescence properties.
Purpose of the Study:
- To synthesize and characterize cubic NaGdF4:Yb/Tm@NaGdF4:Mn core-shell nanoparticles.
- To investigate the energy transfer mechanisms leading to Mn(2+) upconversion emission.
- To explore the role of Gd(3+) lattice and F(-) vacancies in the observed luminescence.
Main Methods:
- Synthesis of core-shell nanoparticles using established chemical methods.
- Characterization using techniques like X-ray diffraction and transmission electron microscopy.
- Optical spectroscopy to study upconversion emission and luminescence lifetime measurements.
Main Results:
- Successful synthesis of cubic NaGdF4:Yb/Tm@NaGdF4:Mn core-shell structures.
- Observation of upconversion emission of Mn(2+) at room temperature.
- Demonstrated energy transfer pathway: Yb→Tm→Gd→Mn.
- Validated Mn(2+) emission via decreased Gd(3+) emission lifetime (941 to 532 μs).
- Evidence of F(-) vacancies around Mn(2+) ions for charge neutrality.
Conclusions:
- Core-shell nanoparticles enable efficient Mn(2+) upconversion emission in lanthanide tetrafluoride hosts.
- Energy transfer and Gd(3+) lattice play critical roles in the upconversion process.
- F(-) vacancies are essential for charge compensation in Mn(2+) doped shells.
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