Turning Ultra-Low Coercivity and Ultra-High Temperature Stability Within 897 K via Continuous Crystal Ordering...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• High-performance soft magnetic materials are crucial for energy conservation and emission reduction.
• A key challenge is balancing temperature stability, high resistivity, high Curie temperature, and high saturation magnetization while maintaining low coercivity.
• Homogeneous microstructures in soft magnetic materials often lead to a trade-off between these properties.

Purpose of the Study:

• To develop a novel soft magnetic material with superior properties at elevated temperatures.
• To overcome the typical trade-offs observed in conventional soft magnetic materials.
• To provide guidance for designing advanced magnetic materials for high-temperature applications.

Main Methods:

• Fabrication of a nanostructured FeCoNiSiAl complex concentrated alloy using a hierarchical structure strategy.
• Characterization of magnetic properties, including intrinsic coercivity, resistivity, and saturation magnetization, across a wide temperature range (up to 897 K).
• Microstructural analysis to understand the relationship between structure and magnetic performance.

Main Results:

• The developed alloy exhibits superior soft magnetic properties up to 897 K.
• It maintains ultra-low intrinsic coercivity (13.6 A m⁻¹ at 297 K) over a broad temperature range.
• High resistivity (138.08 µΩ cm⁻¹ at 297 K) and minimal saturation magnetization attenuation (16.7% at 897 K) were achieved.
• These properties are attributed to a dual-magnetic-state nature with exchange softening from atomic-scale crystal ordering fluctuations.

Conclusions:

• The nanostructured FeCoNiSiAl alloy demonstrates an unusual combination of desirable soft magnetic properties at high temperatures.
• Microstructure control is key to tuning and enhancing the comprehensive performance of such alloys.
• This research offers valuable insights for developing high-temperature soft magnetic materials and related functional materials for sustainable energy applications.