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Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating
Published on: February 20, 2016
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Structural and magnetic properties of core-shell Au/Fe3O4 nanoparticles
L León Félix1,2, J A H Coaquira1, M A R Martínez1
1Laboratory of Magnetic Characterization, Instituto de Física, Universidade de Brasília, DF 70910-900, Brasília, Brazil.
Scientific Reports
|February 7, 2017
Summary
We synthesized gold/iron oxide core-shell nanoparticles, revealing an exchange bias effect due to spin interactions in the iron oxide shell below room temperature.
Area of Science:
- Materials Science
- Nanotechnology
- Condensed Matter Physics
Background:
- Core-shell nanoparticles offer unique properties due to the combination of different materials.
- Gold/iron oxide (Au/Fe3O4) nanostructures are of interest for magnetic and plasmonic applications.
Purpose of the Study:
- To systematically study the synthesis and magnetic properties of Au/Fe3O4 core-shell nanoparticles.
- To investigate the exchange bias effect in these core-shell nanostructures.
Main Methods:
- Synthesis of Au/Fe3O4 core-shell nanoparticles via thermal decomposition.
- Characterization using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM).
- Magnetic property measurements, including temperature-dependent magnetization and exchange bias field (HEX) analysis.
Main Results:
- Successfully synthesized Au/Fe3O4 core-shell nanoparticles with a ~6.9 nm Au core and ~3.5 nm epitaxially grown Fe3O4 shell.
- Observed a thermal blocking state in the Fe3O4 shell below 59 K.
- Demonstrated a significant exchange bias effect below room temperature, appearing around 40 K and increasing with decreasing temperature.
Conclusions:
- The observed exchange bias effect is attributed to the interfacial spin interactions between disordered and ordered regions within the Fe3O4 shell.
- Au/Fe3O4 core-shell nanoparticles exhibit promising magnetic properties for potential applications.
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