Presentation Information
[P2-69]Iron nitride Fe16N2: intrinsic properties, synthesis, stability and bulk magnets
*Imants Dirba1, Jürgen Gassmann2, Oliver Diehl2, Oliver Gutfleisch1 (1. Functional Materials, Institute of Materials Science, Technical University of Darmstadt, 64287 Darmstadt, Germany (Germany), 2. Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS, Aschaffenburger Str. 121, 63457 Hanau, Germany (Germany))
Keywords:
Iron nitride,Fe16N2,rare earth free,permanent magnet
The fascinating phase diagram of iron-nitrogen provides a variety of interesting materials with their magnetic properties tunable in a broad range depending on the nitrogen content. As expected, magnetism correlates with the iron amount, starting from nonmagnetic FeN to ferromagnetic Fe4N with high magnetization and spin polarization and even further to Fe8N. Perhaps the most attention is attracted by the ordered tetragonal superstructure α′′-Fe16N2 due to its unique combination of high saturation magnetization with enhanced magnetocrystalline anisotropy. Unfortunately, the α′′-Fe16N2 phase is metastable and therefore hard to produce in phase-pure form. Moreover, decomposition already below 200 °C [1] hinders large scale production of bulk fully dense magnets using conventional routes. Nevertheless, it has been studied for multiple potential applications, such as rare-earth-free permanent magnets, two-phase nanocomposite magnets [2] as well as biomedical applications [3].In this contribution we provide a comprehensive overview and assessment of the potential magnet performance based on our own experimental results as well as study of the available scientific literature and patents. We report synthesis of α′′-Fe16N2 nanoparticles followed by production of bulk samples by low-temperature consolidation. Magnetic properties and stability are discussed in the context of possible application in permanent magnets.
References
[1] I. Dirba et al., Acta Mater., vol. 123, pp. 214–222, 2017.
[2] I. Dirba et al., J. Magn. Magn. Mater., vol. 518, 2021.
[3] I. Dirba et al., J. Phys. D. Appl. Phys., vol. 56, no. 2, p. 025001, Jan. 2023.
References
[1] I. Dirba et al., Acta Mater., vol. 123, pp. 214–222, 2017.
[2] I. Dirba et al., J. Magn. Magn. Mater., vol. 518, 2021.
[3] I. Dirba et al., J. Phys. D. Appl. Phys., vol. 56, no. 2, p. 025001, Jan. 2023.
