Nd–Fe–B magnets have long been prized for their unparalleled magnetic strength, largely powering the electrification revolution in transportation and renewable energy sectors. However, as the demand for higher output drives the development of larger and thicker magnet components, maintaining coercivity—the magnet’s ability to withstand demagnetizing influences—throughout the entirety of the magnet has remained a formidable challenge. Traditional methods, reliant on incrementally diffusing heavy rare earth elements (HREEs) such as dysprosium or terbium from the magnet’s surface inward, offer improvements but fall short when applied to the interiors of thick magnets.

These conventional processes encounter inherent constraints due to their surface-limited diffusion mechanism. The HREEs coat the magnet’s exterior, slowly permeating inward along grain boundaries, but their penetration depth is insufficient to reinforce the core regions of thick magnets. This divergence results in nonuniform magnetic properties, where the external layers retain high coercivity while the interior remains vulnerable to demagnetization. Compounding this limitation, heavy rare earth elements are costly and subject to geopolitical supply uncertainties, making their widespread industrial use increasingly unsustainable.

KIMS researchers tackled these challenges by conceptualizing and perfecting a sandwich-structured grain boundary diffusion strategy. The innovation lies in layering multiple magnet slices and integrating them with a low-melting-point alloy containing praseodymium—a light rare earth element (LREE). This composite structure effectively generates diffusion paths not only from the exterior surfaces but also from within the interfaces that connect the stacked layers. By introducing the diffusion agent at multiple depths, the technology achieves pervasive enhancement of coercivity throughout thick magnets, a feat previously unattainable.

This multilayered configuration marks a significant departure from established diffusion methodologies, enabling magnet interiors to benefit directly from the diffusion process. Moreover, the selection of praseodymium over traditional HREEs presents a strategic advantage by reducing reliance on scarce, expensive materials without compromising magnetic performance. Through meticulous control of alloy composition and diffusion parameters, the team secured uniform magnetic properties, making thick magnets more viable for high-power applications.

Beyond augmenting coercivity, the researchers addressed another critical issue—eddy current-induced heat generation within magnets operating at high speed. Such heat not only degrades magnetic performance but also diminishes motor efficiency and lifespan. The novel process engineering fosters the formation of a high-resistivity grain boundary structure. This architectural modification impedes the flow of eddy currents, thereby suppressing heat buildup during motor operation.

Importantly, this integration of properties—magnetic, electrical resistivity, and structural bonding—occurs within a single streamlined grain boundary diffusion step. By circumventing the need for separate segmentation, coating, and bonding processes common in traditional manufacturing, the new method promotes simplified and potentially more cost-effective production while enhancing the magnets’ functional characteristics.

The implications of this technological leap extend well beyond laboratory measurements. Enhanced coercivity and reduced heat generation directly translate into more stable, efficient motors that can operate at higher powers and speeds. Consequently, electric vehicles, industrial motors, and wind turbines could benefit from lighter, more powerful, and longer-lasting magnet components, accelerating the global transition toward sustainable energy solutions.

Furthermore, this innovation holds promise for emerging applications requiring exceptionally large and high-performance magnets, such as electric propulsion systems for marine vessels and aerospace components. The ability to manufacture thick magnets with uniform, superior properties broadens the horizons for advanced electromechanical designs and facilitates domestic production capabilities, thereby mitigating supply chain vulnerabilities.

The research team, spearheaded by Su-Min Kim and Jung-Goo Lee under the leadership of President Chul-jin Choi, underscores the transformative potential of integrating coercivity enhancement and resistivity improvements in a unified process. “What distinguishes our technology is its capacity to seamlessly combine enhanced magnetic strength, electrical insulation, and structural integration,” noted Kim. “This represents a paradigm shift in magnet manufacturing with widespread industrial repercussions.”

This technology was rigorously vetted in studies that investigated diffusion kinetics, microstructural evolution, and magnetic performance metrics, thereby affirming its feasibility for practical motor applications. With continued development, researchers envision commercial deployment in next-generation motors, fulfilling the stringent demands of electric vehicles and renewable energy systems.

Funded by South Korea’s Ministry of Trade, Industry and Energy through the Materials and Components Technology Development Program, this research was published in the reputable journal Scripta Materialia on March 18, 2026. The paper details not only the sandwich-structured grain boundary diffusion strategy but also quantitative analyses demonstrating improved coercivity and electrical resistivity in thick Nd–Fe–B magnets.

As the global push for electrification and sustainable energy adoption intensifies, this breakthrough from KIMS represents a seminal advancement in materials science and magnet technology. By resolving long-standing issues related to performance consistency and thermal management in thick magnets, the sandwich-structured diffusion method lays a foundation for more reliable, efficient, and cost-effective magnet-based devices across diverse sectors.

It heralds a future where high-power magnets are no longer hampered by core weakness or excessive heat, thereby enabling electric motors and turbines to achieve unprecedented levels of performance and durability. This technology could become instrumental in addressing energy consumption challenges, enhancing transportation systems, and fostering innovation in electromagnetic device design on a global scale.

Subject of Research: Development of advanced thick Nd–Fe–B magnets with uniform coercivity and high resistivity via sandwich-structured grain boundary diffusion.

Article Title: Development of thick Nd–Fe–B magnets with high coercivity and resistivity via a sandwich-structured grain boundary diffusion strategy.

News Publication Date: March 18, 2026.

Web References:

• Korea Institute of Materials Science (KIMS), https://www.kims.re.kr/?lang=en

References:

• Published article in Scripta Materialia, Impact Factor: 5.6, March 18, 2026.

Image Credits: Korea Institute of Materials Science (KIMS)

Keywords

Magnet technology, grain boundary diffusion, Neodymium–iron–boron magnets, coercivity enhancement, light rare earth elements, praseodymium diffusion, eddy current suppression, high resistivity magnets, electric vehicles, electric motors, renewable energy, materials science.

Synchronous motors, long regarded as workhorses in various high-performance applications, operate on the principle of maintaining synchrony between the rotor’s magnetic field and the stator’s rotating magnetic field. Yet, the challenge of accurately localizing the rotor position during locking—the state in which the rotor is stationary or moving very slowly under load—has persisted as a critical barrier. Traditional sensors often struggle under these conditions, leading to inefficiencies and compromised motor longevity. The team’s innovation unlocks a new frontier by leveraging sophisticated magnetic field detection combined with active manipulation strategies, ultimately offering a robust solution to this longstanding problem.

At the core of this breakthrough lies an advanced system for magnetic localization that employs an array of strategically positioned sensors around the stator, capable of detecting subtle variations in the magnetic flux density as the rotor interacts with the stator’s magnetic field. These sensors deliver high-resolution spatial data that can be processed in real-time, enabling precise determination of the rotor’s angular position without the need for mechanical encoders or additional intrusive hardware components. This sensor network effectively maps the magnetic landscape within the motor’s active zone, capturing dynamic changes that were previously undetectable with conventional methods.

Complementing this localization technique is a suite of algorithms engineered to exploit the magnetic field data for active manipulation of the synchronous motor. By dynamically adjusting the stator currents and magnetic field vectors based on feedback from the sensor array, the system can finely control the rotor’s torque production and positional locking behavior. This closed-loop control architecture represents a significant departure from traditional open-loop or sensor-dependent systems, greatly enhancing responsiveness and stability even under variable load conditions or external disturbances.

One of the standout features of this research is the ability to maintain synchronization in motors experiencing locking torque conditions where prior technologies might falter. The magnetic localization system ensures the rotor can be accurately tracked at near-zero speeds, enabling seamless transitions between start-up, locking, and full-speed operation. This capability is crucial not only for improving motor efficiency but also for minimizing mechanical stress and wear, which, over time, contributes to longer service lifespans and reduced maintenance costs for complex electromechanical systems.

Technically, the team’s methodology involves detailed magnetic field modeling that accounts for rotor eccentricity, stator slotting effects, and temperature-dependent properties of magnetic materials. These factors are integrated into the signal processing workflows to refine the estimation accuracy further. By incorporating machine learning techniques, the system adapts to individual motor characteristics, effectively ‘learning’ optimal control parameters for each device. This adaptive approach ensures that performance is maximized across a wide range of operating conditions and motor designs without requiring exhaustive manual tuning.

The implications for industrial automation are substantial. Robots equipped with these advanced synchronous motors could achieve dramatically improved positional accuracy, enabling delicate tasks that were previously infeasible without bulky or expensive external sensors. Precision assembly lines, surgical robotics, and even autonomous vehicles stand to benefit from motors whose magnetic fields can be localized and manipulated with such finesse. Moreover, renewable energy technologies, including wind turbines and electric vehicle drivetrains, could use this system to optimize energy conversion efficiency and reliability.

From an engineering perspective, the integration of magnetic localization and manipulation into existing synchronous motor architectures is designed to be minimally invasive. The sensor arrays and associated electronics are compact, enabling retrofitting on current motor models with relatively little modification. This scalability makes the technology not only appealing for new equipment development but also as a cost-effective upgrade path, accelerating its deployment across industries and markets.

Environmental impact considerations further underscore the importance of this advancement. By enhancing the efficiency and durability of synchronous motors, the technology contributes to overall energy savings on a global scale. Motors account for a significant portion of industrial electrical consumption, and even marginal improvements in efficiency translate into substantial reductions in carbon emissions. The increased reliability also means fewer replacements and less material waste over the lifecycle of motor-driven systems.

The study also delves into the challenges encountered during development, including mitigating electromagnetic interference and thermal noise that can compromise sensor accuracy. Advanced filtering techniques and sensor shielding strategies were employed to ensure signal integrity. The researchers’ systematic approach to these technical hurdles paves the way for robust, real-world deployment where environmental variables and operational unpredictability can otherwise diminish performance.

Future prospects articulated in the research highlight possibilities for further miniaturization of the sensor matrix and integration with emerging solid-state electronics to create fully embedded smart motors. Such motors would autonomously monitor and adjust their operating conditions in real-time, ushering in an era of self-optimizing machines that can adapt to evolving operational demands and predictive maintenance schedules without human intervention.

Moreover, the research team hints at exploratory work extending magnetic manipulation into multi-motor arrays where coordinated control could achieve novel mechanical behaviors. This concept could revolutionize complex machine assemblies where multiple synchronous motors operate in concert, offering unprecedented levels of flexibility, synchronization, and fault tolerance.

In conclusion, the magnetic localization and manipulation technology developed by Richter, Masjosthusmann, Makushko, and their collaborators represents a landmark achievement in synchronous motor research. The combination of innovative magnetic sensing, dynamic control algorithms, and adaptive learning frameworks positions this technology to redefine the standards for motor precision, efficiency, and durability. The findings, slated for publication in Communications Engineering, are poised to catalyze advancements across a broad spectrum of industrial, medical, and environmental applications, ultimately contributing to smarter, greener, and more reliable electromechanical systems worldwide.

Subject of Research: Magnetic localization and manipulation of locking synchronous motors

Article Title: Magnetic localization and manipulation of locking synchronous motors

Article References:
Richter, M., Masjosthusmann, L., Makushko, P. et al. Magnetic localization and manipulation of locking synchronous motors. Commun Eng 4, 91 (2025). https://doi.org/10.1038/s44172-025-00424-3

Image Credits: AI Generated