Article
Nanoscience & Nanotechnology
Kwangjae Park, Yusuke Hirayama, Jian Wang, Makoto Kobashi
Summary: This study demonstrates the preparation of Sm-Co bulk magnet with remarkable coercivity, excellent temperature coefficient, and thermal stability through the use of unique Sm-Co alloy nanopowder.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Xiao Han, Hoyun Won, Minyeong Choi, S. N. Vijayaraghavan, Zhongqi Liu, Ruigang Wang, Lin Li, Yang-Ki Hong, Feng Yan
Summary: The study deposited an alpha(1) phase alloy film on Pt/TiO2/SiO2/Si substrate and found that the coercivity of the film significantly increased after annealing, attributed to interdiffusion between the alpha(1) phase and the substrate. This led to a large magnetocrystalline anisotropy in the tetragonal L1(0) (Co, Fe, Ni)Pt film.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Wei Tang, Gaoyuan Ouyang, Xubo Liu, Jing Wang, Baozhi Cui, Jun Cui
Summary: The study finds that by introducing a non-magnetic grain boundary phase, the loss of coercivity in MnBi magnets can be significantly reduced, leading to improved performance.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Review
Materials Science, Multidisciplinary
Chao Wang, Ming-Gang Zhu
Summary: Sm-Co permanent magnets are widely used due to their excellent magnetic properties at high temperatures, with the capability to reliably operate at temperatures up to 500 degrees C being their biggest advantage. However, achieving reliable high-temperature magnetic properties depends greatly on alloy composition and technique processes. This review emphasizes the importance of appropriate composition and technique processes for good high-temperature magnetic properties in Sm-Co magnets.
Article
Materials Science, Multidisciplinary
N. S. Anuraag, S. K. Shaw, Sher Singh Meena, R. K. Singh, N. K. Prasad
Summary: Low temperature phase (LTP) MnBi exhibits positive spontaneous exchange bias (SEB) at room temperature, which can be explained by the pinning of ferromagnetic MnBi spins by localized antiferromagnetic clusters. After ball milling, the coercivity and maximum exchange bias field of the samples are significantly improved. Apart from its use as hard magnets, this phenomenon has potential applications in magnetoresistive random access memory (MRRAM) devices and spintronics.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Physical
H. L. Fang, J. Liu, P. W. Huang, M. Y. Li
Summary: The research reveals that adding a proper amount of Cu in MnAl-C permanent magnetic alloy can stabilize phase composition and improve magnetic properties. Cu can form a cellular structure and promote the transformation of magnetic domains within the Mn-rich phase.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Applied
Minyeong Choi, Yang-Ki Hong, Hoyun Won, Gary J. Mankey, Chang-Dong Yeo, Woncheol Lee, Myung-Hwa Jung, Taegyu Lee, Jong-Kook Lee
Summary: The study demonstrates that rare-earth free ferromagnetic MnBi exhibits a positive temperature coefficient of coercivity, but undergoes a structural phase transformation at high temperatures. By controlling the positioning of copper occupancy, it is possible to effectively suppress Mn diffusion and raise the temperature of the phase transformation.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Parashu Kharel, Bhubnesh Lama, Matthew Flesche, Zachary Mehlberg, Buddhi Lamsal, Shah Valloppilly, Yue Zhou, David J. Sellmyer, Tula R. Paudel
Summary: MnBi and MnBi-based materials have potential as rare-earth-free permanent magnets with moderate energy product. Adding carbon during the synthesis of MnBi can reduce the residual Bi content and improve its saturation magnetization. Experimental and computational results show that Mn55Bi45C (x) samples have better magnetic properties, possibly due to the coating of MnBi grains with carbon.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
P. Tozman, H. Sepehri-Amin, K. Hono
Summary: Recent research interest in SmFe12-based permanent magnets has been revived to find alternatives to critical rare earth elements such as Nd and Dy. The intrinsic hard magnetic properties of the Sm(Fe0.8Co0.2)12 compound have been experimentally confirmed to be superior to Nd2Fe14B, but challenges remain in achieving stability and high coercivity in bulk phase.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Multidisciplinary
Xubo B. Liu, Kinjal Gandha, Haobo Wang, Kaustubh Mungale, Uday Kumar Vaidya, Ikenna C. Nlebedim, Mariappan Parans Paranthaman
Summary: Highly dense and magnetically anisotropic rare earth bonded magnets were fabricated using a batch extrusion process and compression molding technology. The magnets had a mixture of Sm-Fe-N and Nd-Fe-B particles with a polyphenylene sulfide binder. The hybrid bonded magnet had a high density and a maximum energy product, with the fine-sized Sm-Fe-N particles filling the gap between the larger Nd-Fe-B particles.
Article
Nanoscience & Nanotechnology
Xin Tang, J. Li, A. K. Srinithi, H. Sepehri-Amin, T. Ohkubo, K. Hono
Summary: The study found that the addition of V element has a significant impact on coercivity, and the ThMn 12-type structure can be stabilized in SmxFe11TiV ribbons, while the coercivity can be significantly increased in optimally-annealed ribbons.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Yutaka Matsuura, Ryuji Tamura, Keisuke Ishigami, Kazushi Sumitani, Kentaro Kajiwara, Tetsuya Nakamura
Summary: The study revealed that the coercivity of (Sm, Ce)(2)(Co, Fe, Cu, Zr)(17) magnets differs from other types of magnets, yet shows similar trends to Ga-doped Nd-Fe-B sintered magnets and ferrite magnets. This suggests that the coercivity of these magnets is determined by the motion of magnetic domain walls.
MATERIALS TRANSACTIONS
(2021)
Article
Chemistry, Physical
H. L. Fang, J. Liu, P. W. Huang, M. Y. Li
Summary: This research systematically investigated the microstructure, phase composition, magnetic properties, and magnetic domain of (Mn55Al45-xCux)(100)C-2 alloys with different Cu contents. The results showed that the addition of an appropriate amount of Cu could stabilize the ε and ferromagnetic τ phases and improve the magnetic properties of the materials.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
J. S. Zhang, Xin Tang, H. Sepehri-Amin, A. K. Srinithi, T. Ohkubo, K. Hono
Summary: An anisotropic bulk SmFe12-based sintered magnet with high coercivity and remanence ratio has been successfully prepared using a conventional liquid sintering process. The magnet consists mainly of Sm(Fe,Ti,V,Al)(12) grains with a ThMn12-type crystal structure and a Sm-rich amorphous intergranular phase. Further research is needed to reduce grain size and engineer the intergranular phase composition to improve coercivity.
Article
Materials Science, Multidisciplinary
H. L. Fang, J. Liu, P. W. Huang, D. W. Shi
Summary: This study doped Bi into the Mn54Al44-xBixC2 alloy system and found that the doped Bi could effectively stabilize the metastable s phase and inhibit the nonmagnetic Al-rich phase formation. The ferromagnetic s phase ratio increased dramatically with increasing Bi doping, and a peak Ms of 81 emu/g was achieved. High coercivity ferromagnetic LTP MnBi phase formed within the Mn54Al44-xBixC2 alloys after annealing, leading to a significant increase in coercivity compared to the initial alloy. The doped Bi improved the thermal and structural stability of the s phase, and the 0.4 Bi doped Mn54Al43.6Bi0.4C2 alloy exhibited high Ms and Hc even after long-term ball milling.
MATERIALS & DESIGN
(2023)
