Tohoku University Technology: Rare-earth free ferromagnetic particle powder showing BHmaxabove 6 MGOe: T19-390_T19-706_T19-709

Realization of α“-Fe16N2 particle powder with high saturation magnetization.

In recent years, the international market price of neodymium has skyrocketed. This is believed to be due to the increasing demand for wind power generation and electric vehicle motors in China, which is promoting decarbonization as a national policy. Additionally, discussions regarding economic security within Japan are becoming active, leading to a strong demand for magnetic materials that do not contain rare earth elements. Among these, there is significant expectation for inexpensive Fe-N based magnetic materials composed solely of iron and nitrogen. In particular, α“-Fe16N2, which is predicted to have a bct structure and high saturation magnetization, is attracting considerable attention. However, α“-Fe16N2 itself is a metastable compound that crystallizes when Fe-N based compounds are annealed, and there are very few reports of it being isolated as a bulk material. The few existing reports involve eutectics of α“-Fe16N2 with stable phases or instances where it only exists for ten days at 100°C, and there are no examples of α“-Fe16N2 being stably isolated as a single phase in bulk form. This invention relates to the stable isolation of α“-Fe16N2 powder.

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