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Robust antiferromagnetic coupling in hard-soft bi-magnetic core/shell nanoparticles
M Estrader1, A López-Ortega2, S Estradé3
11] ICN2-Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, E-08193 Bellaterra, Barcelona, Spain [2] Departament de Química Inorgànica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona, Spain.
Nature Communications
|December 18, 2013
Summary
Researchers demonstrate robust antiferromagnetic coupling in bi-magnetic core-shell nanoparticles. This finding elucidates positive exchange bias and controls magnetic resonance properties for advanced device applications.
Area of Science:
- Materials Science
- Nanotechnology
- Condensed Matter Physics
Background:
- Miniaturization of magnetic devices drives interest in bi-magnetic nanoparticles.
- Reproducing layered magnetic system properties in nanoparticles is a key goal.
- Existing core-shell nanoparticles show some effects like exchange bias but lack others.
Purpose of the Study:
- To demonstrate robust antiferromagnetic (AFM) coupling in core-shell nanoparticles.
- To elucidate positive exchange bias in bi-magnetic systems.
- To regulate resonance field and amplitude in these nanoparticles.
Main Methods:
- Magnetometry
- Ferromagnetic resonance (FMR)
- X-ray magnetic circular dichroism (XMCD)
- Monte Carlo simulations
Main Results:
- Robust AFM coupling demonstrated in iron oxide-manganese oxide core-shell nanoparticles (soft/hard and hard/soft).
- Positive exchange bias elucidated in bi-magnetic systems.
- Remarkable regulation of resonance field and amplitude achieved.
Conclusions:
- AFM coupling in core-shell nanoparticles is robust and experimentally verified.
- This coupling enables positive exchange bias and tunable magnetic resonance.
- Potential for advanced applications using these bi-magnetic core-shell nanoparticles.
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