Nanocrystalline CoMnFeNiGa High Entropy Alloys Exhibiting Room Temperature Ferromagnetism

Strategic Insights -

Researchers at the University of Duisburg-Essen have successfully synthesized and characterized nanocrystalline CoMnFeNiGa high entropy alloys (HEAs). These alloys exhibit room temperature ferromagnetism, a property that can be tuned by controlling the nanoscale structure and applying rapid thermal treatment. The study, published in the journal Faraday Discussions, highlights the potential of HEAs in emerging technologies such as spintronics and nanoelectronics.

Key Takeaways:

  • Researchers at the University of Duisburg-Essen successfully synthesized nanocrystalline CoMnFeNiGa HEAs with a nanocrystalline structure (8 nm) using high energy ball milling (HEBM).
  • The synthesized powders were used to fabricate dense HEA bulk by spark plasma sintering (SPS) and HEA nanoparticles (NPs) by laser fragmentation in liquids (LFL).
  • The study demonstrated that the magnetic behavior of the HEAs can be effectively tuned by nanoscale structural control and rapid thermal treatment.
  • The saturation magnetization of the micropowder and NPs ranged from 19.5 to 33.5 A m kg, while the saturation magnetization of the HEA bulk was 2-4 times larger (88.8 A m kg).
  • A short thermal treatment (1000 K, 30 s) significantly enhanced and increased the Curie temperature of the micropowder, NPs, and bulk material.
  • The coercivity of the NPs increased threefold to 1.8 kA m after thermal treatment.

Statistics:

  • The synthesized nanocrystalline CoMnFeNiGa HEAs exhibited a nanocrystalline structure with an average diameter of 8 nm.
  • The saturation magnetization of the micropowder and NPs ranged from 19.5 to 33.5 A m kg.
  • The saturation magnetization of the HEA bulk was 2-4 times larger (88.8 A m kg) compared to the micropowder and NPs.
  • The Curie temperature of the micropowder, NPs, and bulk material increased significantly after thermal treatment.
  • The coercivity of the NPs increased threefold to 1.8 kA m after thermal treatment.

Sources:

  • NewsRx. Researchers from University of Duisburg-Essen Provide Details of New Studies and Findings in the Area of Nanocrystals (Nanocrystalline CoMnFeNiGa high entropy alloys: room temperature ferromagnetism bridging the gap from bulk to nano). Nanotechnology Weekly. October 20, 2025; p 4292.
  • Faraday Discussions. Nanocrystalline CoMnFeNiGa high entropy alloys: room temperature ferromagnetism bridging the gap from bulk to nano. Royal Soc Chemistry, 2025.