Article
Chemistry, Physical
Munzali Musa, Xin Song, Xianglong Zhou, Wentao Jia, Tao Yuan, Tianyu Ma, Xiaobing Ren
Summary: Grain boundaries with sparse 1:5H precipitates are considered as the primary demagnetization sites in pinning-controlled 2:17-type Sm-Co-Fe-Cu-Zr permanent magnets, leading to poor magnetic properties. TEM investigations reveal that grain boundary regions contain larger 2:17R nanovariants, less SFs, and fewer defects-aggregated cell boundaries compared to grain interiors, indicating that early decomposition preferably occurs at grain boundaries.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Yong Zhang, Pengfei Wu, Yu Lu, Xun Cao, Yizhong Huang, Vincent Gill, Zhiming Li
Summary: The atomic-scale structures of Z-plates in a Zr-alloyed Sm2Co17-type magnet were investigated using aberration-corrected STEM. Zr preferentially replaces dumbbell Sm to form (Sm1/3Zr2/3)Co3 Z-plates, which contribute to the enhancement of magnet performance. Different stacking types of Z-plates were observed, some of which exceed the thickness of double 2/3-stacking and degrade the oxidation resistance of the magnet. The diffusion-controlled mechanisms for the phase transformation from the 2:17R matrix to the 1:3R Z-plates were unraveled.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Alexander Rasul Campbell, Yong Zhang, Richard Stuart Sheridan
Summary: This study examined the influence of grain size in sintered permanent magnets on the growth of an internal oxidation zone (IOZ). The results showed that the smaller-grained magnet had a slower growth rate of IOZ and a smaller irredeemable loss in magnetic remanence (B-r) compared to the larger-grained magnet.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Physical
Sajjad Ur Rehman, Chen Wei, Qingfang Huang, Qingzheng Jiang, Anwar ul Haq, Jun Wang, Zhenchen Zhong
Summary: Reducing the spatial dimensions of spinodally decomposed phases and introducing Ta element can enhance the magnetic properties of Alnico alloys. The addition of Ta improved the intrinsic coercivity of the alloy while maintaining nearly unchanged remanence. Scanning electron microscopy confirmed the unique structure of rod-like Fe-Co rich phase embedded in the matrix phase and the suppression effect of gamma-phase at grain boundaries and triple junctions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Sajjad Ur Rehman, Liang Qiao, Ruibiao Zhang
Summary: This manuscript reports new NdPrFeB/Alnico nanocomposite magnetic materials with enhanced Curie temperatures and maximum magnetic energy products. The Curie temperature of the composite alloys is enhanced by adding low-grade Alnico, and the molecular field penetration improves the temperature stability of the magnets. The maximum energy product is enhanced and the magnetostatic and exchange interactions in the alloys were studied.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Physical
A. M. Gabay, Chaoya Han, Chaoying Ni, G. C. Hadjipanayis
Summary: Iron-rich corners of Sm-Fe-Ti phase diagram and quasi-ternary Sm-Fe0.8Co0.2-Ti phase diagrams are constructed based on experimental investigation. The existence of a high-temperature Th2Ni17-type phase is confirmed. The composition, equilibria, and magnetic anisotropy of cobalt-substituted phases are established.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Dimitris Niarchos, Margaritis Gjoka, Ana Maria Schonhobel, Alex Aubert, Rajasekhar Madugundo, Jose Javier Saiz Garitaonandia, Jose Manuel Barandiaran, George Hadjipanayis
Summary: A series of (Nd1-xSmx)Fe11Ti alloys with the ThMn12 crystal structure have been fabricated to promote a strong uniaxial anisotropy in NdFe11Ti without the need of nitrogenation. The study found that the anisotropy field of the alloys rapidly increases with the incorporation of Sm and is correlated with the quadrupole splitting.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Tihana Mudrinic, Jugoslav Krstic, Biljana Milovanovic, Stefan Pavlovic, Predrag Bankovic, Aleksandra Milutinovic-Nikolic
Summary: The main goals of this study were to characterize aluminasupported cobalt using electrochemical methods, investigate the electro-catalytic activity of different cobalt phases towards glucose, and synthesize glucose sensing materials using mechanochemical approach. The study found that CoAl2O4-A exhibited higher activity towards glucose oxidation compared to Co3O4-A, due to the involvement of tetrahedral Co2+ ion as the active site. The study also demonstrated the effectiveness of mechanochemical synthesis protocols for obtaining glucose-sensing materials. Furthermore, the study highlighted the potential of electrochemical techniques as powerful alternative methods for Co-A surface characterization.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Khaled Aledealat, Bilal Aladerah, Abdalla Obeidat, Abdel-Monem M. Rawashdeh
Summary: This study investigates the influence of nitrogen and oxygen defects on the structural and magnetic properties of CoPt, CoFePt2, and CoNiPt2 alloys using computational methods. The results reveal that the incorporation of nitrogen and oxygen defects significantly affects the magnetic properties of these alloys and provides insights for the development of rare-earth-free permanent magnets.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Engineering, Chemical
Feiwang Wang, Shitao Zhang, Zhiqiang Zhao, Likun Gao, Xiong Tong, Huixin Dai
Summary: This study investigates the effect of the matching relationship between the main permanent magnets (MPMs) and auxiliary permanent magnets (APMs) on the magnetic field distribution and magnetic separation performance of low-intensity magnetic separators (LIMSs). Increasing the width of the MPM can effectively capture farther magnetic particles and improve the separation performance. The height of the APM should be approximately two-thirds of that of the MPM to achieve satisfactory magnetic field distribution and magnetic separation performance.
MINERALS ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Bingjie Liu, Hui Wang, Hao Xu, Jinghua Liu, Chengbao Jiang
Summary: Researchers have revealed the coercivity mechanism of SmCo-based permanent magnets with nanocellular structure through experiments and microscopy, finding that the high magnetocrystalline anisotropy of nanoscale transition zones plays a dominant role in coercivity.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Tetsuji Saito, Daisuke Nishio-Hamane
Summary: The structures and magnetic properties of SmFe5_xTix melt-spun ribbons were studied, revealing that the alloys containing different metastable phases exhibited varying coercivity values as the titanium content increased.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Green & Sustainable Science & Technology
Gwendolyn Bailey, Martina Orefice, Benjamin Sprecher, Mehmet Ali Recai Onal, Enrique Herraiz, Wim Dewulf, Karel Van Acker
Summary: This study compares the environmental impact of primary production routes for neodymium-iron-boron and samarium-cobalt magnets using life cycle assessment. It concludes that the production of samarium-cobalt magnets is not preferable in terms of environmental impact. The uncertainty range tends to be slightly higher for samarium cobalt, indicating more uncertain parameters in the study.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Materials Science, Multidisciplinary
Xianglong Zhou, Tao Yuan, Tianyu Ma
Summary: This study reports a novel stress-aging approach that can significantly shorten the aging time for fabricating high-performance Sm-Co-Fe-Cu-Zr magnets. Applying compressive stress promotes the precipitation of cell boundary phases and accelerates the dissociation of cell edge defects, resulting in high coercivity and high energy product.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
B. Wei, D. Legut, S. Sun, H. T. Wang, Z. Z. Shi, H. J. Zhang, R. F. Zhang
Summary: The study found that certain elements can reduce the degradation rates of both Mg-based and Zn-based alloys, while others will have the opposite effect. Additionally, both tensile and compressive strains can accelerate degradation rates by reducing the activation energy barrier.
