Boosted Nanocrystalline Magnetic Softness via Atomic Immiscibility Induced Chemical Heterogeneity

Area of Science:

• Materials Science
• Condensed Matter Physics

Background:

• Soft magnetic nanocrystalline alloys are vital for power electronics.
• Existing alloys face a trade-off between high saturation magnetic flux density (Bs) and low coercivity (Hc).
• This limitation arises from non-magnetic element incorporation or harsh crystallization processes.

Purpose of the Study:

• To develop a novel nanocrystalline alloy with superior magnetic softness.
• To overcome the limitations of traditional soft magnetic materials.
• To investigate the role of chemical heterogeneity in enhancing magnetic properties.

Main Methods:

• Employing deep supercooling solidification and a strong immiscibility system.
• Preparing Fe86Si1.3B9C2Cu1.7 nanocrystalline alloy.
• Utilizing dynamic magnetization and micromagnetic simulations.

Main Results:

• Achieved superior magnetic softness with Bs = 1.90 T and Hc = 4.0 A m−1.
• Demonstrated enhanced glass-forming ability and atomic immiscibility, promoting dense Cu-rich clusters and Fe-rich regions.
• Revealed that localized chemical heterogeneity leads to a fine nanocrystalline microstructure with decreased grain size.

Conclusions:

• Chemical heterogeneity is a key factor in enhancing soft magnetic properties of nanocrystalline alloys.
• The study presents a novel strategy for tailoring alloy microstructures.
• This approach can potentially improve electrical, mechanical, and catalytic properties.