KIMS to commercialise rare-earth-free manganese-bismuth permanent magnets
April 16, 2025
The Korea Institute of Materials Science (KIMS) has reported a new method for producing manganese-bismuth (Mn-Bi) rare-earth-free permanent magnets. Developed by Dr Ji-Hoon Park and Dr Jong-Woo Kim and their team at the KIMS Division of Nano Materials Research, the method is being commercialised by Novatech Co Ltd and will mark the first industrial application of Mn-Bi permanent magnets.
As the rare earth element market continues to fluctuate significantly, the development of permanent magnets without these elements has become increasingly urgent. While manganese-bismuth has emerged as a promising candidate, fundamental limitations have posed significant challenges to its commercialisation.
To exhibit strong magnetic properties, Mn-Bi powders must maintain a high-purity low-temperature phase (LTP); during high-temperature sintering, the powder is prone to oxidation and phase decomposition, thus making it extremely difficult to adequately densify.
To overcome these limitations, the research team developed a scalable process which includes a newly designed low-temperature sintering technique said to have increased magnet density to over 95% due to the lack of oxidation or phase decomposition. As a result, the magnets consistently achieved a maximum energy product of 10.5 MGOe (Mega-Gauss-Oersted). Through continued research and development efforts, the team aims to achieve a maximum energy product of 12 MGOe.
This technology can be applied across a wide range of industries, including electric vehicle motors, generators, and semiconductor components. It also enables the miniaturisation of electric motors that currently rely on ferrite magnets, while reportedly improving overall efficiency. KIMS highlighted that these Mn-Bi magnets have the potential to replace the conventional magnets used in large quantities in everyday applications and industrial systems such as air conditioning units.
“Through this research, Korea has secured the potential to become the first in the world to commercialise Mn-Bi permanent magnets,” stated lead researcher Dr Park. “If this technology is successfully commercialised, it will significantly reduce dependence on rare-earth magnets and greatly enhance the global competitiveness of domestic companies.”
This research was funded by the National Research Foundation of Korea (NRF), the Korea Institute of Energy Technology Evaluation and Planning (KETEP), and the National Research Council of Science & Technology (NST).
