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Magnetic Composite Formed by Exsolution for Enhanced Exchange Coupling and Breaking the Permeability-Frequency
Mingyue Yuan1, Bangxin Li1, Han-Wen Cheng1
1Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, State Key Laboratory of Coatings for Advanced Equipment, College of Smart Materials and Future Energy, Fudan University, Shanghai, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|July 23, 2026
Summary
Researchers developed advanced ferrite absorbers to overcome the Snoek limit for 5G communications. Their novel composite material enhances magnetic loss and broadband absorption, offering solutions for electromagnetic interference.
Area of Science:
- Materials Science
- Electromagnetics
- Nanotechnology
Background:
- Ferrite absorbers are crucial for high-frequency electronics and 5G systems.
- The Snoek limit restricts complex permeability in the gigahertz range, hindering performance.
- Existing materials face limitations in achieving desired magnetic properties at high frequencies.
Purpose of the Study:
- To overcome the Snoek limit for ferrite-based absorbers.
- To develop materials with enhanced magnetic loss and broadband absorption capabilities.
- To provide a practical route for mitigating 5G electromagnetic interference.
Main Methods:
- In situ thermal-exsolution strategy to create CoFe phases within a W-type hexaferrite matrix.
- Fabrication of coherent alloy/oxide heterostructures at the nanoscale.
- Characterization of magnetic properties, including complex permeability and natural resonance.
Main Results:
- Achieved well-dispersed and rigidly anchored CoFe phases, forming heterostructures.
- Stabilized real permeability and extended natural resonance for magnetic loss across 2-8 GHz, surpassing the Snoek limit.
- Demonstrated a composite with 7.7 GHz absorption bandwidth at 1.4 mm due to balanced impedance matching and enhanced attenuation.
Conclusions:
- The developed composite effectively surpasses the Snoek limit.
- The study links nanoscale magnetic configurations to macroscopic permeability.
- This approach guides the design of high-performance magnetic-response materials for 5G applications.
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