Our society's rapid pace of technological advancement is accompanied by an equally rapid growth in power consumption to meet our needs for 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 the key to improving their efficiency. Soft magnetic materials are metallic materials that respond quickly to external magnetic fields. However, as power electronics operate at increasingly higher frequencies, energy losses in these materials have grown, posing a serious efficiency challenge.

To face this challenge, a research team from the National Institute for Materials Science (NIMS), Tohoku University, and the National Institute of Advanced Industrial Science and Technology (AIST) has developed a new technique for improving the efficiency of soft magnetic materials. This technique controls the nanostructures and magnetic domain structures of iron-based soft amorphous ribbons, achieving more than a 50% reduction in core loss compared to the initial amorphous material. The developed material exhibits particularly high performance in the high-frequency range of several tens of kilohertz - required for applications in next-generation, high-performance transformers and EV drive power supply circuits.

This breakthrough is expected to contribute to the advancement of these technologies, the development of more energy-efficient electric machines, and progress toward carbon neutrality. In the future, the research team plans to fabricate prototype devices such as transformers using the newly developed material and test its integration into actual power conversion circuits.

This research was published in Nature Communications on September 3, 2025.

Publication Details:

Title: Ultra-Low Core Loss in Fe-enriched Soft Magnetic Ribbons Enabled by Nanostructure and High-Frequency Domain Engineering

Authors: Ravi Gautam, Shozo Hiramoto, Nikita Kulesh, Hiroaki Mamiya, Satoshi Okamoto, Nobuhisa Ono, Takeshi Ogasawara, Tadakatsu Ohkubo, Hossein Sepehri-Amin

Journal: Nature Communications

DOI: 10.1038/s41467-025-63139-1

Press release in Japanese