Republished by AIC Engineering. All rights belong to the original publisher; see Source below.

Researchers at Georgetown University have identified a new class of powerful magnets that do not depend on rare-earth or precious metals. The discovery could help advance clean energy systems and consumer technologies, including electric motors, robotics, MRI machines, data storage, and smartphones.

One of the most important qualities of a strong magnet is its ability to keep its magnetization aligned in a preferred direction. This property, known as magnetic anisotropy, is essential for many modern magnetic technologies.

Today, the strongest materials used for permanent magnets rely heavily on rare-earth elements. These materials are costly, environmentally damaging to mine, and vulnerable to supply-chain disruptions and geopolitical instability. In thin-film applications, certain iron-platinum alloys have become leading candidates for next-generation magnetic recording media, but they rely on platinum, a precious metal. Finding high-performance alternatives made from abundant elements has therefore remained a major scientific and technological challenge.

A team led by professors Kai Liu and Gen Yin, along with graduate student Willie Beeson (G’25), in the Department of Physics at Georgetown University College of Arts & Sciences, has now discovered a new type of strong magnet based on high-entropy borides made with abundant transition metals and boron. These materials contain neither rare-earth elements nor precious metals, offering a promising new approach to sustainable magnet design. The findings were published in Advanced Materials.

“We offer a sustainable approach to making strong magnets that may be used for many applications, from future magnetic recording media to permanent magnets,” said Liu, one of the study’s senior authors. “More importantly, this points to the potential to alleviate the dependence on critical materials for magnets and other applications.”

High-entropy alloys are materials made from five or more elements in nearly equal proportions. In recent years, they have become an important platform for discovering new materials because their wide range of possible compositions can produce unusual electronic structures and properties. However, most research on these alloys has focused on chemically disordered cubic structures, which are not ideal for producing strong magnetic anisotropy. That property tends to benefit from lower-symmetry crystal structures.

The Georgetown team addressed this challenge by focusing on high-entropy borides. In these materials, boron helps promote chemical ordering and lower-symmetry crystal structures. The researchers targeted a tetragonal crystal structure, similar to a cube stretched along one side, known as the C16 phase. This structure is already known in boron-based materials made from two or three elements, but it has remained largely unexplored in more complex materials.

Beeson synthesized the high-entropy borides in Liu’s lab using a combinatorial sputtering method. In this process, atoms from multiple target materials mix thoroughly before being collected on a heated substrate. The technique also allowed the team to explore many material compositions quickly. On a single substrate, roughly 50 samples could be produced at the same time under identical conditions, while still varying their compositions.

Key findings

Discovery of a new class of strong magnets: The team created the first high-entropy borides in the C16 crystal structure using earth-abundant 3d transition metals, the elements found in the first row of the d-block of the periodic table. This establishes a new class of ordered high-entropy magnetic materials.

Anisotropy enhancement through chemical mixing: By introducing multiple 3d transition metals and systematically exploring different compositions through combinatorial co-sputtering, the researchers were able to make the magnetization favor a specific direction with much stronger anisotropy.

Record-level performance without rare-earths: The newly discovered quinary boride compositions showed strong magnetic anisotropy approaching that of rare-earth permanent magnets and exceeding previously reported values for rare-earth-free high-entropy materials.

Theory and experiment in agreement: Density functional theory calculations confirmed the experimental trends and showed that optimized electronic structure, especially valence electron concentration and effective magnetic moment, explains the enhanced anisotropy.

“We’re continuing exploring even better permanent magnets or recording media with different compositions on different underlying crystal structures,” said Yin, another senior author of the study. “With the help of machine learning we are hoping to make more rapid progress.”

Impact and applications

The results establish a boron-assisted, high-entropy synthesis strategy for creating strong magnetic anisotropy using only earth-abundant elements. These materials are especially promising for technologies that require high anisotropy, including Heat-assisted magnetic recording media Spintronic devices and magnetic tunnel junctions Energy-efficient, rare-earth-free permanent magnets

By showing that high magnetic anisotropy can be engineered without rare-earth elements and with only abundant transition metals, this research opens new paths toward sustainable magnetic technologies. Beyond magnetism, the study also highlights the broad and still largely unexplored potential of ordered high-entropy materials as a platform for discovering advanced functional properties.

Source

futura-sciences.com (2026-09-28)
Original article: Here's why these new magnets could free us from rare-earth metals
Futura-Sciences
https://futura-sciences.com/en/heres-why-these-new-magnets-could-free-us-from-rare-earth-metals_900566

Here's why these new magnets could free us from rare-earth metals

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