Highlights

• Chinese researchers at Anhui University discovered two microscopic mechanisms limiting heavy rare earth element diffusion in permanent magnets used in EVs and clean energy.
• The study reveals chemical heterogeneity and specific intergranular phases (ZrB₂ and REFe₂) act as barriers, reducing diffusion efficiency of dysprosium and terbium.
• The breakthrough offers a new framework for optimizing magnet design and addressing China's strategic imbalance between scarce heavy rare earths and abundant light rare earths.

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In a potentially significant development for the global rare earth sector, a Chinese research team has identified for the first time the two main microscopic mechanisms that hinder the diffusion efficiency of heavy rare earth elements—materials critical to magnets used in electric vehicles, defense systems, and clean energy technologies.

Professor Wang Shouguo

The breakthrough comes from Professor Wang Shouguo’s group at the School of Materials Science and Engineering at Anhui University (opens in a new tab), in collaboration with Beijing University of Technology (opens in a new tab) and China’s National Key Laboratory for Rare Earth Permanent Magnet Materials (opens in a new tab). Their findings were published in the journal Advanced Functional Materials.

Rare earth permanent magnets are indispensable to high-tech manufacturing and emerging industries. Yet China—the world’s dominantproducer—faces a structural imbalance: strategic heavy rare earths like dysprosium and terbium remain in short supply and inefficiently used, while light rare earths such as lanthanum and cerium are stockpiled in excess.

To address this bottleneck, the researchers proposed a bold new theory: that internal chemical inconsistencies and complex grain boundary structures within high-abundance rare earth magnets are restricting the pathways and rate of heavy rare earth atom diffusion. In short, it’s not just a manufacturing issue—it’s a materials science one.

Using advanced magnetic testing and structural analysis tools, the team demonstrated two key findings:

1. Chemical heterogeneity within crystal grains leads to the selective diffusion of heavy rare-earth atoms.
2. Specific intergranularphases—namely ZrB₂ and REFe₂—act as physical barriers, blocking diffusion and reducing overall efficiency.

This is the first time these two mechanisms have been scientifically confirmed. According to Wang, the discovery offers a fresh theoretical framework for designing more efficient magnet structures and improving the utilization of China’s limited heavy rare earth resources.

Looking ahead, the Anhui team plans to further pursue high-performance magnetic materials through a “theory-driven, demand-oriented” R&D model—signaling China’s intent to maintain technological leadership and deepen control over the rare earth supply chain.

Disclaimer: This article is based on reporting published state-owned entity in China. The information has not yet been independently verified. Readers should consult additional sources for confirmation.

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