Article
Chemistry, Physical
Toujun Zhou, Weizong Bao, Zihan Xu, Mian Zhao, Xiangyun Huang, Weiguo Wei, Renhui Liu, Guoqiang Xie
Summary: This paper presents improvements in the coercivity, mechanical strength, and corrosion resistance of NdFeB magnets by modifying their microstructure using the double alloy method and grain boundary diffusion. The coercivity of magnet increases significantly from 16.66 kOe to 23.78 kOe with 0.64 wt% Tb usage. The overall magnetic performance (OMP) (BH)max (MGOe) + Hcj (kOe) of diffusion magnet improves approximately 7.09%. Furthermore, the mechanical properties and corrosion resistance are enhanced through the diffusion process.
Article
Materials Science, Multidisciplinary
Toujun Zhou, Qian Liu, Xuheng Lu, Weimao Pan, Renhui Liu, Guoqiang Xie, Mianfu Li, Chao Wang
Summary: In this study, the eutectic Tb70Cu20Ga10 alloy was applied to a high magnetic performance NdFeB magnet, resulting in a 60.61% improvement in coercivity without any reduction in maximum energy product and remanence after diffusion. The magnetic vector potential of the magnet was analyzed using the general finite element method. The diffusion mechanism of the eutectic was discussed at various diffusion depths. Tb diffuses into the magnet, forming continuous Tb-rich shells and thin grain boundary phases, which greatly enhance coercivity. Cu, Ga, and O enrich the grain boundary, forming thin RE2(Fe, CuGaO)3 phases, which increase diffusion channels and recover microcracks near the magnet's surface. This diffusion alloy, Tb70Cu20Ga10, has a promising potential for developing high magnetic performance and low-cost sintered NdFeB magnets.
Article
Chemistry, Physical
X. H. Zhang, J. L. Xu, J. M. Luo, Z. Y. Hu, J. Huang, Y. C. Ma
Summary: In this study, Al2O3 ceramic coatings were prepared on sintered NdFeB magnets using cathodic plasma electrolytic deposition (CPED) method. The coatings were analyzed for their surface morphology, composition, corrosion resistance, and magnetic properties. The results show that the coatings mainly consist of γ-Al2O3 and α-Al2O3 phases and exhibit excellent thermal shock resistance and corrosion resistance under hydrothermal conditions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Shuwei Zhong, Munan Yang, Hang Wang, Sajjad Ur Rehman, Xi Yu, Sangen Luo, Longgui Li, Chao Li, Shuhua Xiong, Bin Yang
Summary: In this study, submicron Al, Sn, Zn metal powders were introduced into the precursor powder to improve the infiltration effect and enhance the grain boundary diffusion depth and efficiency of sintered Nd-Fe-B magnets. The addition of Al, Sn, and Zn elements decreased the transformation temperature of the Nd-rich phase and improved the microstructure, promoting the diffusion of Tb into the 2:14:1 phase. The intrinsic coercivity of Al-, Sn-, and Zn-added magnets also increased significantly.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Jie Liu, Libei Jiang, Zukun Yang, Li Wang, Zhibiao Gao, Qianhong Shen, Xianping Fan, Hui Yang
Summary: A novel micro-/nano-structured coating for corrosion resistance of sintered NdFeB was developed by studying the effect of micro/nanomaterials on the composite coating and proposing mechanisms to enhance corrosion resistance. The coated epoxy composite with micro/nanostructure showed improved corrosion resistance, with a longer salt spray test time compared to the pure epoxy coating.
Article
Chemistry, Physical
Erhao Wang, Caihai Xiao, Jiayi He, Cifu Lu, Mozaffar Hussain, Renheng Tang, Qing Zhou, Zhongwu Liu
Summary: The use of a grain boundary diffusion process with ZnO as the diffusion source has significantly enhanced the coercivity and corrosion resistance of sintered Nd-Fe-B magnets. The coercivity of the magnets increased significantly while the formation of oxides at triple junctions improved the corrosion resistance of the diffused magnets.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Jiaying Jin, Yongming Tao, Xinhua Wang, Zeyu Qian, Wang Chen, Chen Wu, Mi Yan
Summary: The concurrent improvements of corrosion resistance and coercivity in Ce-substituted Nd-Ce-Fe-B sintered magnets were achieved through engineering the intergranular phase using (Nd, Pr)H-x additive. The formation of corrosion-resistant intergranular phase and continuous grain boundaries enhanced the corrosion resistance and coercivity, respectively. These findings are significant for the development of high-performance Nd-Ce-Fe-B permanent magnets.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Tengfei Wu, Shuai Cao, Mingpeng Kou, Yuheng Xie, Guangfei Ding, Shuai Guo, Bo Zheng, Renjie Chen, Minglong Zhong, Aru Yan
Summary: This study investigated the influence of rare earths and non-rare earth metallic elements on the diffusion effect of low Tb content alloy diffusion sources in commercial NdFeB sintered magnets. The results showed that the coercivity of the magnets significantly increased with moderate amounts of metallic elements, but deteriorated when the total amounts of metallic elements reached a certain level. Microstructure analyses revealed that the excellent diffusion effects contributed to the coercivity enhancements, with deeper Tb diffusion depths and distinguishable core-shell structures.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Sumin Kim, Hyun-Sook Lee, Woo Hyun Nam, Donghwan Kim, Weon Ho Shin, Jong Wook Roh, Wooyoung Lee
Summary: The magnetic properties and thermal stability of Tb-diffused Nd-Fe-B magnets were investigated, showing that diffusion temperature plays a key role in controlling thermal stability. Magnets fabricated at high diffusion temperatures exhibited good coercivity but poor thermal stability, while those prepared at lower temperatures showed the best thermal stability. The microstructure with diffused Tb atoms was found to be mainly responsible for the enhanced thermal magnetic stability in the magnets.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Jingbin Huang, Min Huang, Fang Wang, Zhanyong Wang, Jian Zhang
Summary: The use of magnetron sputtering film as a diffusion source has been successfully applied in the industrial production of grain-boundary-diffusion magnets. This paper investigates the use of multicomponent diffusion sources to optimize the microstructure and improve the magnetic properties of NdFeB magnets.
Article
Chemistry, Physical
H. S. Maurya, J. Jayaraj, R. J. Vikram, K. Juhani, F. Sergejev, K. G. Prashanth
Summary: This study compares the TiC-430 L ferritic stainless steel cermets manufactured using conventional spark plasma sintering (SPS) and metal additive manufacturing (AM) processes. The results show that the AM process produces cermets with finer microstructures, better mechanical properties, and improved corrosion resistance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Chen Haibo, Zheng Jingwu, Fu Yongcheng, Liu Youhao, Yi Xiaofei, Chen Jingwu, Qiao Liang, Huang Xiulian, Ying Yao, Cai Wei, Li Wangchang, Yu Jing
Summary: The corrosion resistance of rare earth permanent magnet material NdFeB was enhanced by electrodeposited Cu-graphene (Cu-GR) composite films, improving hydrophobicity and hardness. The best protective effect for sintered NdFeB samples was achieved with Cu-GR composite films prepared from the plating solution containing 0.3 g.L-1 of graphene.
RARE METAL MATERIALS AND ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
J. Chen, J. L. Xu, J. Huang, L. Dai, M. S. Xue, J. M. Luo
Summary: The T-ZnOw/PDMS-MAO composite coating, consisting of zinc oxide whisker and polydimethylsiloxane, was successfully applied on sintered NdFeB magnets via micro-arc oxidation treatment. The composite coating showed no significant impact on the magnetic properties of NdFeB magnets but greatly improved corrosion resistance, demonstrating excellent superhydrophobicity.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Chemistry, Applied
Hongyi Yang, Liangsong Duan, Pengjie Zhang, Guangqing Xu, Jiewu Cui, Jun Lv, Wei Sun, Bingshan Li, Dongmei Wang, Yucheng Wu
Summary: Tannic acid was used to modify multiwall carbon nanotubes to enhance their dispersibility in water, forming TCNTs hybrids. The TCNTs enhanced epoxy coatings showed superior corrosion resistance, as demonstrated by electrochemical experiments.
JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Dong Zhao, Fugang Liu, Yu Gao, Pan Jiang, Limin Liu, Mingjing Zhao, Shaoqing Ren, Wenli Pei
Summary: Heavy rare earth (such as Dy) thermal diffusion process is a promising method to increase the coercivity of sintered NdFeB magnets and optimize their thermal performance. In this study, the Dy evolution process and the mechanism of coercivity improvement were systematically analyzed. Dy diffused along the grain boundaries, forming uniform and continuous grain boundaries of Dy-rich phases, which significantly increased the coercivity of the magnet. Simultaneously, Dy diffused into the main phase to form a thin layer with higher magnetocrystalline anisotropy, inhibiting the nucleation of reversed magnetic domains and further improving intrinsic coercivity. However, over diffusion led to decreased performance of the magnet.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Bibhutibhusan Nayak, S. Narayana Jammalamadaka
Summary: This article presents a method for remote detection of bovine serum albumin (BSA) using modified cantilever beam magnetometry (CBM). By combining a magnetostrictive Fe70Ga30 cantilever with optical detection technique, researchers were able to detect high concentrations of BSA remotely. The results of this study demonstrate the potential of this method in estimating the magnetostriction of thin films.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yu Hao, R. E. Camley, Z. Celinski
Summary: Magnetic particles have various applications and their magnetic state is determined by their size and the strength of an applied magnetic field. Numerical simulations were performed to study the effect of an applied field on the critical size of single-domain magnetic particles, and the critical field at which a particle becomes single-domain was determined.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Nitesh Singh, Naresh Kumar, Dharohar Sahadot, Anil Annadi, Vidyadhar Singh, Murtaza Bohra
Summary: The unique magnetic properties of FM/AFM and hard-FM/soft-FM nanocomposite thin films have significant relevance for numerous applications. The composition and performance of different magnetic phases in the nanocomposite films can be significantly affected by the laser ablation conditions and annealing temperature.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Alya Ali Musaed, Samir Salem Al-Bawri, Khaled Aljaloud, Wazie M. Abdulkawi, Mohammad Tariqul Islam, Mandeep Jit Singh, Zaini Sakawi, Husam Hamid Ibrahim
Summary: This research presents a wideband tunable metamaterial for body-centric applications in the millimeter-wave frequency band. The proposed metamaterial has a wide operating frequency range and enhanced gain, making it suitable for improving the antenna performance in 5G wireless communication systems.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Binod K. Rai, Boris Maiorov, Krzysztof Gofryk, Patrick O'Rourke, Catherine Housley, Henry Ajo, Asraf Sawon, Arjun K. Pathak, Narayan Poudel, Qiang Zhang, Travis J. Williams, Matthias Frontzek
Summary: This manuscript reports on the structural and magnetic properties of NdCuGa3. The study confirmed the crystal structure and magnetic phase transition of NdCuGa3 using XRD, neutron diffraction, magnetization, and specific heat measurements. The neutron diffraction data further confirmed the antiferromagnetic phase of NdCuGa3.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Haonan Li, Cong Li, Hailiang Huang, Guodong Hao, Fei Wang
Summary: The electronic structure and ferroelectric-ferromagnetic coupling properties of Y-doped and vacancy-containing GaN-ZnO heterojunctions are systematically investigated. The magnetism in vacancy-containing systems is generated by the spin polarization of unpaired electrons induced by cationic vacancies, while in Y-doped systems, bound magnetic polarons are formed by the orbital hybridization of s-state and d-state electrons of Y-doped elements.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Muhammad Ijaz, Hafeez Ullah, Bandar Ali Al-Asbahi, Mati Ullah Khan, Zaheer Abbas, Sana Ullah Asif
Summary: M-type BaFe11.4-xAlxCo0.6O19 hexaferrites with Al3+ substitutions were synthesized using the co-precipitation method followed by Sonochemical process. The synthesized materials were characterized using XRD, FTIR, UV-vis spectroscopy, VSM, SEM, and LCR meter. The results showed that aluminum doping decreased the band gap and enhanced the magnetic and dielectric properties of the hexaferrites, making them suitable for various applications.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Oleg I. Utesov
Summary: The elementary excitations spectrum of anisotropic frustrated antiferromagnets in the fan phase is discussed. It is found that the low-energy part of the spectrum consists of a gapless phason branch with linear dispersion and a gapped optical branch corresponding to the fan structure amplitude oscillations. In the high-energy part of the spectrum, the excitations are similar to the magnons of the fully polarized phase.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Alexander Ya. Simonovskii, Alexander A. Yanovskii, Arthur R. Zakinyan
Summary: In this study, the departure frequency of vapor bubbles during boiling of ferrofluid in a horizontal magnetic field is experimentally investigated. Two methods, visual and inductive, are used to measure the frequency of bubble departure. The results show that the bubble departure frequency can decrease with increasing magnetic field strength and increase with increasing temperature of the heat-emitting surface. A linear stability analysis is conducted to analyze the influence of the magnetic field on the frequency of bubble formation during ferrofluid boiling.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Oleg Heczko, Michal Rames, Vit Kopecky, Petr Vertat, Michal Varga, Ladislav Straka
Summary: Heusler Ni-Mn-Ga alloys are multiferroic materials that exhibit magnetic shape memory (MSM) phenomena. By doping transition elements into Ni2MnGa alloys, the transformation temperatures can be modified and complex behaviors can be observed, such as the variation in saturation magnetization and the effects of elemental substitution on compound properties.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Carlos Ariel Samudio Perez, Ariel Flaig de Marchi
Summary: This study investigates the electronic and magnetic properties of the Full-Heusler Fe2MnAs alloy using first-principles calculations. The alloy may form spontaneously and exhibits a ferromagnetic order and high spin-polarization. It can be transformed into a half-metal by contracting the lattice constant. Additionally, certain defects contribute to the spin-polarization of the alloy, making it a fully half-metallic material.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Satish Geeri, Aditya Kolakoti, Prasadarao Bobbili
Summary: In this study, an electromagnetic wave-absorbing material was fabricated using a polymer composite material with fiber orientation and Multiwall Carbon Nanotubes as filler materials, along with a Perfect Electric Conducting material. The experiments demonstrated strong electromagnetic absorbing properties for the composites with PEC-coated and non-PEC-coated materials. Mechanical, thermal, and morphological analysis confirmed the similar trend in properties. CRITIC analysis helped identify the sequence order of sustaining properties for the fabricated composites.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yankai Chen, Ruoxue Zhang, Yukai An
Summary: The piezoelectricity, valley character, and magnetic properties of 2H-VS2 monolayer were studied, revealing its potential applications in spintronics and valleytronics due to its bipolar magnetic semiconductor characteristics and superior physical properties.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Leonardo S. Lima
Summary: This study investigates the thermodynamic quantities, such as entropy, specific heat, and magnetic susceptibility, in the next-nearest-neighbors Heisenberg model on a honeycomb-kagome lattice. The linear spin-wave approach is applied to obtain the temperature-dependent behavior of these quantities. Additionally, the entanglement negativity, a quantifier of quantum entanglement, and the spin Hall conductivity are also studied. The results show that all the thermodynamic quantities, as well as the entanglement negativity and spin Hall conductivity, exhibit an increasing trend with temperature. Furthermore, it is found that all the analyzed quantities approach zero in the low-temperature limit, consistent with experimental observations.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Zhaoxing Wang, Maximilian Kai Reimann, Wang Chen, Yikun Zhang, Rainer Poettgen
Summary: The Mo2FeB2-type compounds RE2Ga2Mg (RE = Tm, Er, Ho) exhibit a large magnetocaloric effect, making them promising for cryogenic magnetic cooling applications.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)