Document Type : Review Article
Authors
1 Department of Materials Science and Engineering, Iran University of Science and Technology (IUST)
2 R&D Department, Mapna Generator Engineering and Manufacturing Company (PARS)
Abstract
Permanent Magnets (PMs) are employed in many modern devices, thanks to their unique properties. Electrical machines, i.e., motors and generators, are a major application of PMs, which produce the required magnetic field. When there are severe constraints on the weight and dimensions of the device (e.g. in hybrid electric vehicles or wind turbines), using high-energy PMs would be of crucial importance. Currently, PMs which contain Rare-Earth Elements (REEs), e.g. Sm-Co and Nd-Fe-B, are the most commonly used and the most powerful practical PMs. However, the monopolized supply of the raw materials required for the production of these PMs as well as the recent rise in their global price, have encouraged researchers to investigate some methods for reducing the consumption of REEs or substituting other PMs for those with REEs. This paper studies the state of the art advances in developing PMs with less or no REEs and the corresponding achievements.
Keywords
Main Subjects
[1] O. Ben Dor, S. Yochelis, S. P. Mathew, R. Naaman, and Y. Paltiel, “A chiral-based magnetic memory device without a permanent magnet,” Nat. Commun., vol. 4, p. 2256, 2013.
[2] C. T. Sherman, P. K. Wright, and R. M. White, “Physical Validation and testing of a MEMS piezoelectric permanent magnet current sensor with vibration canceling,” Sensors Actuators A. Phys., vol. 248, pp. 206–213, 2016.
[3] J. M. D. Coey, “Permanent magnet applications,” J. Magn. Magn. Mater., vol. 248, no. 3, pp. 441–456, 2002.
[4] J. V. M. Mcginley, M. Ristic, and I. R. Young, “A permanent MRI magnet for magic angle imaging having its field parallel to the poles,” J. Magn. Reson., vol. 271, pp. 60–67, 2016.
[5] F. Jimenez-villacorta and L. H. Lewis, “Advanced Permanent Magnetic Materials,” NANOMAGNETISM, pp. 160–189, 2014.
[6] F. JACEK and GIERAS, “Permanent Magnet Motor Technology: Design and Applications”. CRC Press Taylor & Francis Group, 2010.
[7] M. Lak, “Speed Control for Direct Drive Permanent Magnet Wind Turbine,” no. Figure 1, pp. 317–321, 2014.
[8] J. D. Widmer, R. Martin, and M. Kimiabeigi, “Sustainable Materials and Technologies Electric vehicle traction motors without rare earth magnets,” SUSMAT, vol. 3, pp. 7–13, 2015.
[9] Z. Xu, A. Al-Timimy, and M. Degano, “Thermal management of a permanent magnet motor for an directly coupled pump,” in Industrial Electronics Society IECON 2016 - 42nd Annual Conference of the IEEE, 2016, pp. 1749–1754.
[10] I. I. Abdalla, T. Ibrahim, and N. Bin Mohd Nor, “Development and optimization of a moving-magnet tubular linear permanent magnet motor for use in a reciprocating compressor of household refrigerators,” Int. J. Electr. Power Energy Syst., vol. 77, pp. 263–270, 2016.
[11] L. I. X. Jime, “Perspectives on Permanent Magnetic Materials for Energy Conversion and Power Generation,” Metall Mater Trans A 44 (Suppl 1), 2–20 (2013).
[12] “Rare-Earth Permanent Magnets, Vacodym and Vacomax,” Vacuumschmelze GmbH Co. KG, http//www.vacuumschmelze.com/fileadmin/Medienbiliothek_2010/Downloads/DM/VACODYM-VACOMAX-PD002_2015_en.pdf.
[13] B. D. Cullity and C. D. Geraham, “introduction to Magnetic materilas,” John Wiley & Sons, 2009.
[14] E. Furlani, “permanent magnets and electrochemical devices.” Elsevier, 2001.
[15] A. Goldman, “MODERN FERRITE TECHNOLOGY. Springer”, 2006.
[16] Steve Constantinides, “Market Outlook for Ferrite, Rare Earth and Other Permanent Magnets: 2015 to 2025,” Magn. 2017, pp. 1–43, 2016.
[17] R. C. Pullar, “Hexagonal ferrites: A review of the synthesis, properties and applications of hexaferrite ceramics,” Prog. Mater. Sci., vol. 57, no. 7, pp. 1191–1334, Sep. 2012.
[18] D. Chen, D. Zeng, and Z. Liu, “Synthesis, structure, morphology evolution and magnetic properties of single domain strontium hexaferrite particles,” Mater. Res. Express, vol. 3, no. 4, p. 45002, Apr. 2016.
[19] A. J. Moulson and J. M. Herbert, “Electroceramics: materials, properties, applications”. John Wiley & Sons Ltd, 2003.
[20] J.M.D. Coey, “Magnetism and magnetic materilas.” Cambridge University Press, 2010.
[21] O. Gutfleisch, M. a Willard, E. Brück, C. H. Chen, S. G. Sankar, and J. P. Liu, “Magnetic materials and devices for the 21st century: stronger, lighter, and more energy efficient.,” Adv. Mater., vol. 23, no. 7, pp. 821–42, Feb. 2011.
[22] US Geological Survey, “Mineral Commodity Summaries 2016 Mineral Commodity Summaries 2016,” 2016.
[23] J.M.D. Coey, “Perspective and Prospects for Rare Earth Permanent Magnets,” Engineering, https://doi.org/10.1016/j.eng.2018.11.034
[24] H. S. Yoon, C. J. Kim, K. W. Chung, S. D. Kim, J. Y. Lee, and J. R. Kumar, “Solvent extraction, separation and recovery of dysprosium (Dy) and neodymium (Nd) from aqueous solutions: Waste recycling strategies for permanent magnet processing,” Hydrometallurgy, vol. 165, pp. 27–43, 2016.
[25] R. Schulze and M. Buchert, “Estimates of global REE recycling potentials from NdFeB magnet material,” Resour. Conserv. Recycl., vol. 113, pp. 12–27, 2016.
[26] V. Prakash, Z. H. I. Sun, J. Sietsma, and Y. Yang, “Simultaneous Electrochemical Recovery of Rare Earth Elements and Iron from Magnet Scrap: A Theoretical Analysis”. Elsevier Inc., 2015.
[27] “Critical materilas sterategy.” U.S. department of energy, 2010.
[28] T. Ogawa, Y. Ogata, R. Gallage, N. Kobayashi, N. Hayashi, Y. Kusano, S. Yamamoto, K. Kohara, M. Doi, M. Takano, and M. Takahashi, “Challenge to the Synthesis of αʺ-Fe16N2 Compound Nanoparticle with High Saturation Magnetization for Rare Earth Free New Permanent Magnetic Material,” vol. 73007.
[29] T. Shima, T. Moriguchi, S. Mitani, and K. Takanashi, “Low-temperature fabrication of L10 ordered FePt alloy by alternate monatomic layer deposition,” Appl. Phys. Lett., vol. 80, no. 2, p. 288, 2002.
[30] P. Campbell, “permanent magnet materials and their application.” Cambridge University Press, 1994.
[31] W. Gong, X. Zhao, W. Fan, J. Feng, A. Lin, J. He, W. Liu, and Z. Zhang, “Structure, Magnetic Properties, and Coercivity Mechanism of Rapidly Quenched MnxGa Ribbons,” IEEE Trans. Magn., vol. 51, no. 11, pp. 1–4, 2015.
[32] D. Jiles, “introduction to magnetism and magnetic materilas.” SPRINGER-SCENCE+BUSINESS MEDIA, 1991.
[33] N. A. Spaldin, “Magnetic materilas”. Cambridge University Press, 2011.
[34] S. P. Gubin, “Magnetic Nanoparticles”. WILEY-VCH Verlag GmbH & Co.KGaA, 2009.
[35] X. H. Tan, S. F. Chan, K. Han, and H. Xu, “Combined effects of magnetic interaction and domain wall pinning on the coercivity in a bulk Nd₆₀Fe₃₀Al₁₀ ferromagnet.,” Sci. Rep., vol. 4, p. 6805, Jan. 2014.
[36] Zhongwu Liu a, Jiayi He , Qing Zhou, Youlin Huang, Qingzheng Jiang,” Development of non-rare earth grain boundary modification techniques for Nd-Fe-B permanent magnets”, Journal of Materials Science & Technology,vol. 98, pp.51–61, 2022.
[37] L. Zheng, B. Cui, L. Zhao, W. Li, and G. C. Hadjipanayis, “Sm2Co17 nanoparticles synthesized by surfactant-assisted high energy ball milling,” J. Alloys Compd., vol. 539, pp. 69–73, Oct. 2012.
[38] S. Sugimoto, “Current status and recent topics of rare-earth permanent magnets,” J. Phys. D. Appl. Phys., vol. 44, p. 64001, 2011.
[39] S. Pan, “Rare Earth Permanent-Magnet Alloys-High Temperature Phase Transformation: In Situ and Dynamic Observation and Its Application in Materials Design”. Springer, 2013.
[40] J. S. M. J. Noguesa, J. Sort, V. Langlais, V. Skumryev, S. Surinach and Baro, “Exchange bias in nanostructures,” Phys. Rep., vol. 22, pp. 65–117, 2005.
[41] J. S. Jiang and S. D. Bader, “Rational design of the exchange-spring permanent magnet,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64214, Feb. 2014.
[42] A. López-Ortega, M. Estrader, G. Salazar-Alvarez, A. G. Roca, and J. Nogués, “Applications of exchange coupled bi-magnetic hard/soft and soft/hard magnetic core/shell nanoparticles” Phys. Rep., vol. 553, no. 2014, pp. 1–32, Feb. 2015.
[43] W.-B. Cui, Y. K. Takahashi, and K. Hono, “Nd2Fe14B/FeCo anisotropic nanocomposite films with a large maximum energy product” Adv. Mater., vol. 24, no. 48, pp. 6530–5, Dec. 2012.
[44] G. Giannopoulos, L. Reichel, A. Markou, I. Panagiotopoulos, and V. Psycharis, “Optimization of L1 0 FePt / Fe 45 Co 55 thin films for rare earth free permanent magnet applications,” vol. 223909, pp. 1–8, 2015.
[45] V. Neu, S. Sawatzki, M. Kopte, C. Mickel, and L. Schultz, “Fully epitaxial, exchange coupled SmCo 5/Fe multilayers with energy densities above 400 kJ/m 3,” IEEE Trans. Magn., vol. 48, no. 11, pp. 3599–3602, 2012.
[46] N. Route and N. Magnets, “A Novel Rout for the Preparation of Nanocomposit Magnets,” pp. 1441–1444, 2000.
[47] S. Sun, “Exchange-coupled nanocomposite magnets by nanoparticle,” no. November, pp. 395–398, 2002.
[48] R. Goyal, N. Arora, A. Kapoor, S. Lamba, and S. Annapoorni, “Exchange hardening in FePt/Fe3Pt dual exchange spring magnet: Monte Carlo modeling,” J. Alloys Compd., vol. 695, pp. 1014–1019, 2017.
[49] J. Zhou, R. Skomski, X. Li, W. Tang, G. C. Hadjipanayis, and D. J. Sellmyer, “Permanent-Magnet Properties of Thermally Processed FePt and FePt – Fe Multilayer Films,” no. SEPTEMBER, pp. 2802–2804, 2002.
[50] B. Balasubramanian, B. Das, R. Skomski, W. Y. Zhang, and D. J. Sellmyer, “Novel nanostructured rare-earth-free magnetic materials with high energy products” Adv. Mater., vol. 25, no. 42, pp. 6090–3, Nov. 2013.
[51] a. D. Volodchenkov, Y. Kodera, and J. E. Garay, “Synthesis of strontium ferrite/iron oxide exchange coupled nano-powders with improved energy product for rare earth free permanent magnet applications,” J. Mater. Chem. C, 2016.
[52] R. W. McCallum, L. Lewis, R. Skomski, M. J. Kramer, and I. E. Anderson, “Practical Aspects of Modern and Future Permanent Magnets” Annu. Rev. Mater. Res., vol. 44, no. 1, pp. 451–477, Jul. 2014.
[53] A. Poorbafrani, H. Salamati, and P. Kameli, “Exchange spring behavior in Co0.6Zn0.4Fe2O4/SrFe10.5O16.75 nanocomposites,” Ceram. Int., vol. 41, no. 1, pp. 1603–1608, 2015.
[54] R. Safi, A. Ghasemi, and R. Shoja-Razavi, “The role of shell thickness on the exchange spring mechanism of cobalt ferrite/iron cobalt magnetic nanocomposites,” Ceram. Int., vol. 43, no. 1, pp. 617–624, 2017.
[55] Y. Jiang, M. Al Mehedi, E. Fu, Y. Wang, L. F. Allard, and J.-P. Wang, “Synthesis of αʺ-Fe16N2 compound Free-Standing Foils with 20 MGOe Magnetic Energy Product by Nitrogen Ion-Implantation,” Nat. Sci. Reports, vol. 6, no. November 2015, p. 25436, 2016.
[56] Y. Jiang, V. Dabade, L. F. Allard, E. Lara-Curzio, R. James, and J. P. Wang, “Synthesis of αʺ-Fe16N2 Compound Anisotropic Magnet by the Strained-Wire Method,” Phys. Rev. Appl., vol. 6, no. 2, pp. 1–10, 2016.
[57] I. Dirba, C. A. Schwobel, L. V. B. Diop, M. Duerrschnabel, L. Molina-Luna, K. Hofmann, P. Komissinskiy, H. J. Kleebe, and O. Gutfleisch, “Synthesis, morphology, thermal stability and magnetic properties of αʺ-Fe16N2 nanoparticles obtained by hydrogen reduction of -Fe2O3 and subsequent nitrogenation,” Acta Mater., vol. 123, pp. 214–222, 2017.
[58] T. Ogi, Q. Li, S. Horie, A. Tameka, T. Iwaki, and K. Okuyama, “α-hematite for rare-earth-free magnet applications Synthesis process,” Adv. Powder Technol., 2016.
[59] Y. Jiang, B. Himmetoglu, M. Cococcioni, and J.-P. Wang, “DFT calculation and experimental investigation of Mn doping effect in Fe16N2,” AIP Adv., no. 5, p. 56007, 2016.
[60] J.-P. Wang, S. He, and Y. Jiang, “Iron nitride permanent magnet and technique for forming iron nitride permanent magnet,” 2014.
[61] H. Zeng, M. L. Yan, N. Powers, and D. J. Sellmyer, “Orientation-controlled nonepitaxial L10 CoPt and FePt films,” Appl. Phys. Lett., vol. 80, no. 13, p. 2350, 2002.
[62] A. M. Montes-Arango, L. G. Marshall, A. D. Fortes, N. C. Bordeaux, S. Langridge, K. Barmak, and L. H. Lewis, “Discovery of process-induced tetragonality in equiatomic ferromagnetic FeNi,” Acta Mater., vol. 116, pp. 263–269, 2016.
[63] T. Kojima, M. Ogiwara, M. Mizuguchi, M. Kotsugi, T. Koganezawa, T. Ohtsuki, T.-Y. Tashiro, and K. Takanashi, “Fe-Ni composition dependence of magnetic anisotropy in artificially fabricated L10-ordered FeNi films.,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64207, Feb. 2014.
[64] L. H. Lewis, a Mubarok, E. Poirier, N. Bordeaux, P. Manchanda, a Kashyap, R. Skomski, J. Goldstein, F. E. Pinkerton, R. K. Mishra, R. C. Kubic, and K. Barmak, “Inspired by nature: investigating tetrataenite for permanent magnet applications.,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64213, Feb. 2014.
[65] E. Poirier, F. E. Pinkerton, R. Kubic, R. K. Mishra, N. Bordeaux, A. Mubarok, L. H. Lewis, J. I. Goldstein, R. Skomski, and K. Barmak, “Intrinsic magnetic properties of L10 FeNi obtained from meteorite NWA 6259,” J. Appl. Phys., vol. 117, no. 17, p. 17E318, May 2015.
[66] M. Kotsugi, H. Maruyama, N. Ishimatsu, N. Kawamura, M. Suzuki, M. Mizumaki, K. Osaka, T. Matsumoto, T. Ohkochi, and T. Ohtsuki, “Structural, magnetic and electronic state characterization of L10-type ordered FeNi alloy extracted from a natural meteorite.,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64206, Feb. 2014.
[67] J. Liu and K. Barmak, “Interdiffusion in nanometric Fe/Ni multilayer films,” J. Vac. Sci. & Technol. A Vacuum, Surfaces, Film., vol. 33, no. 2, p. 21510, 2015.
[68] L. Néel, J. Pauleve, R. Pauthenet, J. Laugier, and D. Dautreppe, “Magnetic Properties of an Iron—Nickel Single Crystal Ordered by Neutron Bombardment,” J. Appl. Phys., vol. 35, no. 3, p. 873, 1964.
[69] T. Shima, M. Okamura, S. Mitani, and K. Takanashi, “Structure and magnetic properties for L10-ordered FeNi films prepared by alternate monatomic layer deposition,” J. Magn. Magn. Mater., vol. 310, no. 2, pp. 2213–2214, Mar. 2007.
[70] T. Kojima, M. Mizuguchi, and K. Takanashi, “Growth of L10-FeNi thin films on Cu(001) single crystal substrates using oxygen and gold surfactants,” Thin Solid Films, vol. 603, pp. 348–352, 2016.
[71] J. M. D. Coey, “New permanent magnets; manganese compounds,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64211, Feb. 2014.
[72] R. Ducher, R. Kainuma, and K. Ishida, “Phase equilibria in the Ni-rich portion of the Ni-Ga binary system,” Intermetallics, vol. 15, no. 2, pp. 148–153, 2007.
[73] Q. Zeng, I. Baker, and Z. C. Yan, “Nanostructured Mn-Al permanent magnets produced by mechanical milling,” J. Appl. Phys., vol. 99, no. 8, pp. 16–19, 2006.
[74] A. Chaturvedi, R. Yaqub, and I. Baker, “A comparison of τ-MnAl particulates produced via different routes,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64201, Feb. 2014.
[75] a Pasko, M. LoBue, E. Fazakas, L. K. Varga, and F. Mazaleyrat, “Spark plasma sintering of Mn-Al-C hard magnets.,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64203, Feb. 2014.
[76] N. Singh, R. Shyam, N. K. Upadhyay, and a Dhar, “Development of Rare-Earth Free Mn-Al Permanent Magnet Employing Powder Metallurgy Route,” IOP Conf. Ser. Mater. Sci. Eng., vol. 73, p. 12042, Feb. 2015.
[77] M. Gjoka, C. Sarafidis, G. Giannopoulos, and D. Niarchos, “Effects of milling conditions on the magnetic properties of MnBi alloys,” 2015 IEEE Int. Magn. Conf. INTERMAG 2015.
[78] J. Park, Y.-K. Hong, J. Lee, W. Lee, S.-G. Kim, and C.-J. Choi, “Electronic Structure and Maximum Energy Product of MnBi,” Metals (Basel), vol. 4, no. 3, pp. 455–464, Aug. 2014.
[79] Ronald, Pirich, David, and Larson, “Directional solidification and densification of permanent magnets having single domain size MnBi particles,” 1988.
[80] J. B. Yang, Y. B. Yang, X. G. Chen, X. B. Ma, J. Z. Han, Y. C. Yang, S. Guo, a. R. Yan, Q. Z. Huang, M. M. Wu, and D. F. Chen, “Anisotropic nanocrystalline MnBi with high coercivity at high temperature,” Appl. Phys. Lett., vol. 99, no. 8, p. 82505, 2011.
[81] H. Kronmüller, J. B. Yang, and D. Goll, “Micromagnetic analysis of the hardening mechanisms of nanocrystalline MnBi and nanopatterned FePt intermetallic compounds,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64210, Feb. 2014.
[82] N. V Rama Rao, a. M. Gabay, and G. C. Hadjipanayis, “Anisotropic fully dense MnBi permanent magnet with high energy product and high coercivity at elevated temperatures,” J. Phys. D. Appl. Phys., vol. 46, no. 6, p. 62001, 2013.
[83] J. Cui, J. P. Choi, G. Li, E. Polikarpov, J. Darsell, N. Overman, M. Olszta, D. Schreiber, M. Bowden, and T. Droubay, “Thermal stability of MnBi magnetic materials.,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64212, Feb. 2014.
[84] D. T. Zhang, S. Cao, M. Yue, W. Q. Liu, J. X. Zhang, and Y. Qiang, “Structural and magnetic properties of bulk MnBi permanent magnets,” J. Appl. Phys., vol. 109, no. 7, p. 07A722, 2011.
[85] 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,” J. Alloys Compd., vol. 615, no. S1, pp. S285–S290, 2015.
[86] L. Zhu, S. Nie, K. Meng, D. Pan, J. Zhao, and H. Zheng, “Multifunctional L10-Mn1.5Ga films with ultrahigh coercivity, giant perpendicular magnetocrystalline anisotropy and large magnetic energy product.,” Adv. Mater., vol. 24, no. 33, pp. 4547–51, Aug. 2012.
[87] R. Rejali, D. H. Ryan, Z. Altounian, C. B. Boyer, Q. Lu, M. Wang, H. Zhang, and M. Yue, “Crystal structure and magnetism of the MnxGa (1.15 ≤ x ≤ 2.0) rare-earth-free permanent magnet system,” AIP Adv., vol. 6, no. 5, pp. 1–8, 2016.
[88] B. Z. Cui, M. Marinescu, and J. F. Liu, “Ferromagnetic tetragonal L10-Type MnGa isotropic nanocrystalline microparticles,” IEEE Trans. Magn., vol. 49, no. 7, pp. 3322–3325, 2013.
[89] Q. Lu, M. Wang, H. Zhang, and M. Yue, “Microstructure and Improved Coercivity of Mn 1.33 Ga Nanoflakes by Surfactant-Assisted Ball Milling", IEEE International Magnetic Conference, 2015.
[90] H. Zhao, W. Y. Yang, Z. Y. Shao, G. Tian, D. Zhou, X. P. Chen, Y. H. Xia, L. Xie, S. Q. Liu, H. L. Du, J. Z. Han, C. S. Wang, Y. C. Yang, and J. B. Yang, “Structural evolution and magnetic properties of L10-type Mn 54.5 Al 45.5-x Ga x (x = 0.0, 15.0, 25.0, 35.0, 45.5) phase,” J. Alloys Compd., vol. 680, pp. 14–19, 2016.
[91] J. N. Feng, W. Liu, W. J. Gong, X. G. Zhao, D. Kim, C. J. Choi, and Z. D. Zhang, “Magnetic Properties and Coercivity of MnGa Films Deposited on Different Substrates,” J. Mater. Sci. Technol., 2016.
[92] J. FENG “Magnetic properties and coercivity mechanism of MnGa films” pp. 2015, 2015.
[93] I. P. and G. V. E. Anagnostopoulou, B. Grindi, L.-M. Lacroix, F. Ott, “Dense arrays of cobalt nanorods as rare-earth free permanent magnets,” Nanoscale, vol. 8, no. 7, pp. 4020–4029, 2016.
[94] M. Sarr, N. Bahlawane, D. Arl, M. Dossot, E. McRae, and D. Lenoble, “Atomic layer deposition of cobalt carbide films and their magnetic properties using propanol as a reducing agent,” Appl. Surf. Sci., vol. 379, pp. 523–529, 2016.
[95] V. G. Harris, Y. Chen, A. Yang, S. Yoon, Z. Chen, A. L. Geiler, J. Gao, C. N. Chinnasamy, L. H. Lewis, C. Vittoria, E. E. Carpenter, K. J. Carroll, R. Goswami, M. A. Willard, L. Kurihara, M. Gjoka, and O. Kalogirou, “High coercivity cobalt carbide nanoparticles processed via polyol reaction: a new permanent magnet material,” J. Phys. D. Appl. Phys., vol. 43, p. 165003, 2010.
[96] V. Harris and Sharon, “Cobalt Carbide-Based nanoparticle Permanent Magnet Materials,” patent No. EP2475483A1, 2015.
[97] O. H. Materials, “Novel Functional Magnetic Materials”. 1999.
[98] B. Balamurugan, B. Das, W. Y. Zhang, R. Skomski, and D. J. Sellmyer, “Hf-Co and Zr-Co alloys for rare-earth-free permanent magnets.,” J. Phys. Condens. Matter, vol. 26, no. 6, p. 64204, Feb. 2014.
[99] A. K. Pathak, M. Khan, K. A. Gschneidner, R. W. McCallum, L. Zhou, K. Sun, K. W. Dennis, C. Zhou, F. E. Pinkerton, M. J. Kramer, and V. K. Pecharsky, “Cerium: An unlikely replacement of dysprosium in high performance Nd-Fe-B permanent magnets,” Adv. Mater., vol. 27, no. 16, pp. 2663–2667, 2015.
[100] M. A. Susner, B. S. Conner, B. I. Saparov, M. A. McGuire, E. J. Crumlin, G. M. Veith, H. Cao, K. V. Shanavas, D. S. Parker, B. C. Chakoumakos, and B. C. Sales, “Flux growth and characterization of Ce- substituted Nd2Fe14B Single Crystal,” J. Magn. Magn. Mater., 2016.
[101] Z. B. Li, M. Zhang, B. G. Shen, F. X. Hu, and J. R. Sun, “Variations of phase constitution and magnetic properties with Ce content in Ce-Fe-B permanent magnets,” Mater. Lett., vol. 172, pp. 102–104, 2016.
[102] Z. B. Li, B. G. Shen, M. Zhang, F. X. Hu, and J. R. Sun, “Substitution of Ce for Nd in preparing R2Fe14B nanocrystalline magnets,” J. Alloys Compd., vol. 628, pp. 325–328, 2015.
[103] K. CHEN, S. GUO, X. FAN, G. DING, L. CHEN, R. CHEN, D. LEE, and A. YAN, “Coercivity enhancement of Ce-Fe-B sintered magnets by low-melting point intergranular additive,” J. Rare Earths, vol. 35, no. 2, pp. 158–163, 2017.
[104] B. Peng, T. Ma, Y. Zhang, J. Jin, and M. Yan, “Improved thermal stability of Nd-Ce-Fe-B sintered magnets by Y substitution,” Scr. Mater., vol. 131, pp. 11–14, 2017.
[105] E. Isotahdon, E. Huttunen-Saarivirta, and V.-T. Kuokkala, “Characterization of the microstructure and corrosion performance of Ce-alloyed Nd-Fe-B magnets,” J. Alloys Compd., vol. 692, pp. 190–197, 2017.
[106] T. Saito and K. Kikuchi, “Production of Sm-Fe-N bulk magnets by the spark plasma sintering method with dynamic compression,” J. Alloys Compd., 2016.
[107] Q. Fang, X. An, F. Wang, Y. Li, J. Du, W. Xia, A. Yan, J. P. Liu, and J. Zhang, “Journal of Magnetism and Magnetic Materials The structure and magnetic properties of Sm – Fe – N powders prepared by ball milling at low temperature,” J. Magn. Mater., vol. 410, pp. 116–122, 2016.
[108] M. Yue, Y. Q. Li, R. M. Liu, W. Q. Liu, Z. H. Guo, and W. Li, “Abnormal size-dependent coercivity in ternary Sm – Fe – N nanoparticles,” vol. 637, pp. 297–300, 2015.
[109] Y. Hirayama, A. K. Panda, T. Ohkubo, and K. Hono, “Scripta Materialia High coercivity Sm 2 Fe 17 N 3 submicron size powder prepared by polymerized-complex and reduction – diffusion process,” SMM, vol. 120, pp. 27–30, 2016
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