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Surface-Spin-Induced Magnetic Loss Enhancement in Ultralight Electromagnetic Absorbers
Ruimin Ren1, Ke Yang1,2, Chichong Lu1
1Department of Chemistry, School of Advanced Materials and Future Technology, Beijing Technology and Business University, Beijing, China.
Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
|June 26, 2026
Summary
Researchers developed ultralight magnetic absorbers using hollow Fe3O4 nanoparticles. Controlling hollowness enhances magnetic loss, improving electromagnetic wave absorption (EMA) and reducing material density for miniaturization.
Area of Science:
- Materials Science
- Nanotechnology
- Electromagnetics
Background:
- Electromagnetic wave absorption (EMA) materials face limitations in achieving low density due to intrinsic magnetic loss.
- Developing lightweight and effective EMA materials is crucial for miniaturization and advanced applications.
Purpose of the Study:
- To investigate a novel strategy for enhancing magnetic loss capacity in EMA materials by controlling surface atom spin.
- To explore the relationship between the hollowness of Fe3O4 nanoparticles and their magnetic loss properties for improved EMA.
Main Methods:
- Synthesis of hollow Fe3O4 nanoparticles with controlled hollow rates (0-54.1%).
- Characterization of magnetic properties, focusing on surface atom moment and body moment.
- Evaluation of electromagnetic wave absorption performance, including effective absorption bandwidth and loss tangent.
Main Results:
- Magnetic loss capacity is primarily dependent on surface atom moment, not body moment.
- Hollow Fe3O4 nanoparticles (54.1% hollow) showed a ~20% enhancement in the imaginary part of permeability (µ'') over 2-18 GHz.
- Effective absorption bandwidth (≤-5 dB) at 2.0 mm broadened to 11.91 GHz, with a significant density reduction to 48.9% of solid samples.
Conclusions:
- Controlling surface atom spin through nanoparticle hollowness is an effective strategy to boost magnetic loss and EMA performance.
- Ultralight hollow Fe3O4 nanoparticles offer promising solutions for next-generation lightweight and miniaturized electromagnetic wave absorbers.
- The findings provide theoretical and practical guidance for designing advanced magnetic absorbers with superior performance and reduced density.
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