One step pressing-annealing to produce LTP MnBi magnets
Keywords:
Rare-earth free magnets, Manganese bismuth, Pressing, AnnealingAbstract
The production process for the high-purity low-temperature-phase (LTP) manganese bismuth (MnBi) magnets requires arc-melting, grinding and annealing materials under inert atmosphere. However, the formation of MnO is practically unavoidable during these steps since both Mn and MnBi are easily oxidized even by trace amounts of oxygen. In this work, an oxygen-free pressing-annealing system is developed to facilitate the synthesis of LTP MnBi with minimal oxidization. The semi-automatic pressing is carried out by using the compression piston and the load cell is used to measure the pressing force. The copper plate and cylindrical container are heated by nichrome filament heating. Mn and Bi precursors in powder form are simultaneously pressed and annealed allowing one step formation of LTP MnBi in argon atmosphere chamber. The vibrating sample magnetometry reveals the hysteresis loop of MnBi samples with ferromagnetic characteristics.Downloads
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O. Gutfleisch, M. A.Willard, E. Bruck, C. H. Chen, S. G, Sankar, and J. Liu, "Magnetic materials and devices for the 21st century: Stronger, lighter, and more energy efficient," Advanced Materials, vol. 23, pp. 821-842, 2011.
Y. C. Chen, G. Gregori, A. Leineweber, F. Qu, C. C. Chen, T. Tietze, H. Kronmüller, G. Schütz, and E. Goering, "Unique high-temperature performance of highly condensed MnBi permanent magnets," Scripta Materialia, vol. 107, pp. 131–135, 2015.
N. Poudyal and J. P. Liu, "Advances in nanostructured permanent magnets research," Journal of Physics D: Applied Physics, vol. 46, pp. 043001, 2013.
L. Bingbing, M. Yilong, S. Bin, L. Chunhong, C. Dengming, S. Jianchun, Z. Qiang, and Y. Xueguo, "Preparation and magnetic properties of anisotropic MnBi powders," Physica B: Condensed Matter, vol. 530, pp. 322-326, 2018.
J. Cui, J. P. Choi, G. Li, E. Polikarpov, J. Darsell, N. Overman, M. Olszta, D. Schreiber, M. Bowden, T. Droubay, M. J. Kramer, N. A. Zarkevich, L. L. Wang, D. D. Johnson, M. Marinescu, I. Takeuchi, Q. Z. Huang, H. Wu, H. Reeve, N. V. Vuong, and J. P. Liu, "Thermal stability of MnBi magnetic materials," Journal of Physics: Condensed Matter, vol. 26, pp. 064212, 2014.
M. A. Bohlmann, J. C. Koo, and J. H. Wise, "Mn-Al-C for permanent magnets", Journal of Applied Physics, vol. 52, pp. 2542, 1981.
W. Xie, E. Polikarpov, J. P. Choi, M. E. Bowden, K. Sun, and J. Cui, "Effect of ball milling and heat treatment process on MnBi powders magnetic properties," Journal of Alloys and Compounds, vol. 680, pp. 1-5, 2016.
Y. Mitsui, K. Oikawa, K. Koyama, and K. Watanabe, "Thermodynamic assessment for the Bi–Mn binary phase diagram in high magnetic fields," Journal of Alloys and Compounds, vol. 577, pp. 315-319, 2013.
V. V. Nguyen and T. X. Nguyen, "Effects of microstructures on the performance of rareearth-free MnBi magnetic materials and magnets," Physica B: Condensed Matter, vol. 532, pp. 103-107, 2018.
T. Charoensuk and C. Sirisathitkul, "Effects of heat treatment and composition on ball-milled MnBi and MnBi/Co magnets," Digest Journal of Nanomaterials and Biostructures, vol. 13, pp. 609-614, 2018.
V. V. Nguyen and T. X. Nguyen, "An approach for preparing high-performance MnBi alloys and magnets," Journal of Electronic Materials, vol. 46, pp. 3333-3340, 2017.
J. Zamora, I. Betancourt, and I. A. Figueroa, "Coercivity mechanism of rare-earth free MnBi hard magnetic alloys," Revista Mexicana de Fisica, vol. 64, pp. 141-144, 2018.
K. Oikawa, Y. Mitsui, K. Koyama, and K. Anzai, "Thermodynamic assessment of the BiMn system," Materials Transactions, vol. 52, pp. 2032-2039, 2011.
Y. C. Chen, S. Sawatzki, S. Ener, H. SepehriAmin, A. Leineweber, G. Gregori, F. Qu, S. Muralidhar, T. Ohkubo, K. Hono, O. Gutfleisch, H. Kronmüller, G. Schütz, and E. Goering, "On the synthesis and microstructure analysis of high performance MnBi," AIP Advances, vol. 6, pp. 125301, 2016.
S. Kim, H. Moon, H. Jung, S. M. Kim, H. S. Lee, H. Choi-Yim, and W. Lee, "Magnetic properties of large-scaled MnBi bulk magnets," Journal of Alloys and Compounds, vol. 708, pp. 1245-1249, 2017.
V. Ly, X. Wu, L. Smillie, T. Shoji, A. Kato, A. Manabe, and K. Suzuki, "Low-temperature phase MnBi compound: A potential candidate for rare-earth free permanent magnets," Journal of Alloys and Compounds, vol. 615, pp. S285-S290, 2014.
D. T. Zhang, W. T. Geng, M. Yue, W. Q. Liu, J. X. Zhang, J. A. Sundararajan, and Y. Qiang, "Crystal structure and magnetic properties of MnxBi100-x (x = 48, 50, 55 and 60) compounds," Journal of Magnetism and Magnetic Materials, vol. 324, pp. 1887-1890, 2012.
N. Poudyal, X. Liu, W. Wang, V. V. Nguyen, Y. Ma, K. Gandha, K. Elkins, J. P. Liu, K. Sun, M. J. Kramer, and J. Cui, "Processing of MnBi bulk magnets with enhanced energy product," AIP Advances, vol. 6, pp. 056004, 2016.
V. V. Nguyen, N. Poudyal, X. B. Liu, J. P. Liu, K. Sun, M. J. Kramer, and J. Cui, "Novel processing of high-performance MnBi magnets," Materials Research Express, vol. 1, pp. 036108, 2014.
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