In a significant stride towards sustainable and affordable magnetic materials, researchers have made notable progress in developing rare-earth-free iron-based permanent magnets. This advancement, led by Sunbeom Park from the Department of Materials Science and Engineering at Seoul National University, could reshape the energy sector by providing a more secure and cost-effective alternative to traditional rare-earth magnets.
The growing demand for secure, sustainable, and affordable magnetic materials has drawn significant attention to rare-earth-free Fe-based permanent magnets. This review integrates recent advances from atomic-scale theory to bulk processing. We first outline the fundamental parameters that govern permanent-magnet performance, such as saturation magnetization (Ms), magnetocrystalline anisotropy, Curie temperature (Tc), and microstructural factors. We then survey four principal material families. The first is Fe–Co alloys whose anisotropy is enhanced through lattice strain and light-element doping. The second is chemically ordered Fe–Ni, tetrataenite, originally discovered in meteorites. The third is nitrogen-rich iron phases typified by α″‐Fe16N2. The fourth is iron phosphides and borides such as Fe2P and Fe–B. Although calculations predict outstanding magnetic strength, experimental results remain limited by phase instability, grain‐size effects, and processing constraints. To bridge this gap, we highlight four complementary research directions: strain engineering, heteroatom doping, deliberate microstructure control, and data‐driven ab initio calculations. Coordinated progress in these areas could yield Fe‐based magnets with high coercivity and robust magnetization, enabling practical devices for electrified transport, renewable‐energy conversion, and compact electronics without costly rare‐earth elements.
Permanent magnets are crucial components in various energy technologies, including electric vehicles, wind turbines, and compact electronics. However, the reliance on rare-earth elements for these magnets poses challenges related to cost, supply chain security, and environmental impact. The research, published in the journal MetalMat (translated to English as “Metal Materials”), explores four principal families of Fe-based magnets, each with unique properties and potential applications.
One of the most promising candidates is the Fe–Co alloy, which enhances its magnetic anisotropy through lattice strain and light-element doping. “The Fe–Co alloys show great potential due to their enhanced magnetic properties and the ability to fine-tune their performance through doping and strain engineering,” said Park.
Another intriguing material is tetrataenite, a chemically ordered Fe–Ni alloy originally discovered in meteorites. This material has garnered attention for its high coercivity and thermal stability, making it an excellent candidate for high-performance magnets.
The research also highlights nitrogen-rich iron phases, such as α″‐Fe16N2, and iron phosphides and borides like Fe2P and Fe–B. These materials offer unique magnetic properties and could be tailored for specific applications through advanced processing techniques.
Despite the promising theoretical predictions, experimental results have been limited by phase instability, grain-size effects, and processing constraints. To overcome these challenges, the researchers propose four complementary research directions: strain engineering, heteroatom doping, deliberate microstructure control, and data-driven ab initio calculations.
“By coordinating progress in these areas, we can develop Fe-based magnets with high coercivity and robust magnetization, enabling practical devices for electrified transport, renewable-energy conversion, and compact electronics without costly rare-earth elements,” Park explained.
The implications of this research are far-reaching. As the world transitions to renewable energy and electrified transport, the demand for high-performance, sustainable magnets will only grow. The development of rare-earth-free Fe-based magnets could not only reduce costs but also enhance the security and sustainability of the energy sector.
This research represents a significant step forward in the quest for sustainable and affordable magnetic materials. As the scientific community continues to explore and refine these Fe-based magnets, the potential for transformative impact on the energy sector becomes increasingly evident. The findings, published in MetalMat, provide a comprehensive overview of the current state and future directions of this promising field, offering a glimpse into a future where rare-earth-free magnets play a pivotal role in powering the world’s energy needs.