A research team from NIMS, Tohoku University and AIST has developed a new technique for controlling the nanostructures and magnetic domain structures of iron-based soft amorphous ribbons, achieving more than a 50% reduction in core loss compared with the initial amorphous material. The developed material exhibits particularly high performance in the high-frequency range of several tens of kilohertz—required for next-generation, high-frequency transformers and EV drive power supply circuits. This breakthrough is expected to contribute to the advancement of these technologies, development of more energy-efficient electric machines and progress toward carbon neutrality. This research was published in Nature Communications on September 3, 2025.
Background
Amid rapid growth in power consumption by AI-focused data centers, electric vehicles and other applications, efficient energy use has become a critical challenge. In power electronics—the technology that converts and supplies electricity—the performance of soft magnetic materials used in transformers, inductors and other components is key to improving their efficiency. Soft magnetic materials are metallic materials that respond quickly to external magnetic fields, and this fast response should be with minimum energy loss. However, as power electronics operate at increasingly higher frequencies, energy losses in these materials have grown, posing a serious efficiency challenge.
Key Findings
The joint research team recently developed a new technique for precisely controlling the nanostructures and magnetic domain structures inside iron-based soft amorphous ribbons. Using this technique, they achieveda reduction in core loss of more than 50% compared with the initial amorphous ribbons, particularly in the high-frequency range of up to several tens of kilohertz required for applications such as high-performance transformers and EV drive power supply circuits (Figure).
Future Outlook
The research team plans to fabricate prototype devices such as transformers using the newly developed material and to test its integration into actual power conversion circuits.
Other Information
- This project was carried out by a research team consisting of Ravi Gautam (Postdoctoral Researcher, Research Center for Magnetic and Spintronic Materials (CMSM), NIMS), Hiroaki Mamiya (Chief Researcher, CMSM, NIMS), Tadakatsu Ohkubo (Deputy Director, CMSM, NIMS), Hossein Sepehri-Amin (Group Leader, CMSM, NIMS), Nikita Kulesh (Research Fellow, International Center for Young Scientists, NIMS), Shozo Hiramoto (Researcher, Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University (TU)), Satoshi Okamoto (Professor, IMRAM, TU), Nobuhisa Ono (PhD student, IMRAM, TU) and Takeshi Ogasawara (Senior Researcher, Core Electronics Technology Research Institute, AIST).
This work was supported by the MEXT's Innovative Power Electronics Technologies (INNOPEL) program (grant number: JPJ009777).
- This research was published in Nature Communications, an open access journal, on September 3, 2025.
