Article
Materials Science, Multidisciplinary
Zhixiang Xia, Guanglong Xu, Xiaoma Tao, Jiang Wang, Yuwen Cui
Summary: The study focused on phase equilibria in the Mg-rich corner of the Mg-Nd-Sc ternary system, revealing significant ternary solubility in the Mg-3(Mg, Nd, Sc) phase. Meanwhile, Mg41Nd5 showed negligible ternary solubility at all three temperatures. The Mg_hcp phase exhibited a narrow homogeneity range at different temperatures.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Chemistry, Physical
Yuheng Xie, Shuai Cao, Xuejing Cao, Tengfei Wu, Mingpeng Kou, Zhi Jia, Guangfei Ding, Shuai Guo, Renjie Chen, Xincai Liu, Aru Yan, Zhiyi Xu
Summary: This study systematically investigated the magnetic properties and microstructures of sintered Nd-Fe-B magnets with different Nd-Cu powder additions and their corresponding diffused magnets using Tb-Cu alloys. The results showed that the enhancement of coercivity after diffusion was positively correlated with the intergranular phase proportion of the base substrates. Furthermore, the analysis of microstructures revealed that the higher coercivities were mainly attributed to the deeper diffusion depths of Tb elements and the presence of Nd-rich grain boundary phases in the base substrates, which facilitated the diffusion process.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Dan Wu, Wei-Qiang Liu, Ming Yue, Qiong Wu, Dong-Tao Zhang, Qing-Mei Lu, Xu-Liang Li, Jing-Wu Chen
Summary: The coercivity, microstructure, and magnetic domain structure of Nd-Fe-B sintered magnets by grain boundary diffusion process (GBDP) with TbH3 nanoparticles were systematically investigated. The analysis showed that a core-shell structure can increase coercivity and identified the presence of both GR and AR through magnetic domain structure analysis.
Article
Chemistry, Physical
Hao Zhan, Yinan Wang, Chuanxiao Peng, Juntao Yu, Zilong Wang, Jiakai Hu, Xinyuan Bai, Yang Luo, Li Wang
Summary: To improve the diffusion characteristics of heavy rare earth in the grain boundary, the effects of diffusion process and the ratio of Tb and Cu during the layered deposition process on the magnetic properties of Tb-Cu diffused Nd-Fe-B magnets were systematically investigated. The coercivity of the diffused magnet was most enhanced with RTb/Cu = 4:1, increasing from 10.86 kOe to 21.80 kOe. Cu significantly improved the composition homogenization of diffused magnets. The highest utilization efficiency of Tb reached 43.96 kOe/wt% in the designed diffused magnet. Moreover, the reduced demagnetization risk of sintered Nd-Fe-B magnets was verified using finite element method based on the experimental temperature characteristics of the magnet. (c) 2023 Elsevier B.V. All rights reserved.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Shuai Guo, Xiao Yang, Xiaodong Fan, Guangfei Ding, Shuai Cao, Bo Zheng, Renjie Chen, Aru Yan
Summary: The grain size has a crucial effect on the diffusion efficiency and depth of Tb element in Nd-Fe-B magnets. Larger grain size results in a higher increment in coercivity after Tb diffusion process. Grain refinement leads to narrowing and discontinuity of the grain boundary phase, which is unfavorable for diffusion and decreases the diffusion efficiency.
Article
Materials Science, Multidisciplinary
Hao Zhan, Chuanxiao Peng, Yuzhao Xue, Xianrui Wang, Xiao Lin, Xinyuan Bai, Li Wang
Summary: By investigating the impact of deposition sequences on the magnetic properties of sintered Nd-Fe-B magnets, it was found that the deposition of an appropriate amount of Cu can increase the diffusion depth of Tb, while excessive Cu deposition reduces the diffusion efficiency of Tb.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Zhanjia Wang, Ming Yue, Weiqiang Liu, Yuqing Li, Haihui Wu, Youhao Liu, Shanshun Zha, Xiaofei Yi, Dongtao Zhang, Qingmei Lu, Hongguo Zhang
Summary: A new solid-liquid phase separation diffusion method was reported in this study, which significantly enhanced the permanent magnetic performance of Nd-Fe-B magnets, particularly the demagnetization curve squareness, by avoiding the evident Tb gradient commonly seen in current GBD magnets.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Jiayi He, Jiali Cao, Jinwen Hu, Zhigao Yu, Xuhang Zhang, Hongya Yu, Huayun Mao, Zhongwu Liu
Summary: A comparative study on coating methods of adhesive coating and sputtering deposition was conducted to evaluate their effects on the surface state of diffused magnet and the process consumption of heavy rare earths (HREs). The results show that sputtering deposition can significantly enhance the coercivity of the magnet and reduce the consumption of Tb.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Enxiang Yang, Weiyang Jin, Chao Man, Xiaolian Liu, Song Fu, Lan Bo, Shuainan Xu, Luyao Zhao, Zhi Li, Zhen Shi, Menglin Yu, Lizhong Zhao, Xuefeng Zhang
Summary: Grain boundary diffusion process has been applied for enhancing coercivity of Nd-Fe-B magnets by forming core-shell structure with less Tb consumption. However, excessively thick and asymmetric Tb-rich shells near the shallow diffused surface have minor contribution to coercivity enhancement and consume more Tb resources.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Sangen Luo, Munan Yang, Zaiping Xu, Tongyun Zhao, Sajjad Ur Rehman, Xi Yu, Shuwei Zhong, Haitao Wang, Chaoxiang Jin, Qiang Ma, Bin Yang
Summary: This paper investigates the effect of grain size in the diffusion matrix on the grain boundary diffusion mechanism of Tb element. The results show that with only 0.75 wt. % TbF3 diffusion, the intrinsic coercivity increases significantly for the magnet with finer average grain size compared to the coarse-grain magnet. The increase in intrinsic coercivity is attributed to the increase in defect density and the higher grain orientation caused by grain refinement, which leads to improved diffusion efficiency and magnetic properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Zhanjia Wang, Yuqing Li, Haihui Wu, Ming Ji, Hongguo Zhang, Weiqiang Liu, Ming Yue
Summary: Grain boundary diffusion (GBD) Nd-Fe-B sintered magnets were prepared using a newly developed solid-liquid phase separation diffusion (SepD) technique and a currently popular solid-liquid phase simultaneous diffusion (SimD) technique. The magnetic properties, microstructures, and magnetic domain morphologies of the magnets diffused with different Tb contents using the two techniques were investigated. The SepD magnet with 0.25 wt% Tb exhibited similar coercivity and a stronger maximum energy product compared to the SimD magnet with 0.50 wt% Tb, showing higher Tb availability. Moreover, the new diffusion technique allowed Tb to diffuse deeper into the magnet and distribute more homogeneously around the surface region of the Nd2Fe14B crystal grains, forming the crucial core-shell structure without undesired enrichment in the surface area of the magnet. As a result, the squareness factor significantly increased from 0.842 for the SimD magnet to 0.925 for the SepD magnet with a thickness of 8 mm.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Z. Wang, T. T. Sasaki, Y. Une, T. Ohkubo, K. Hono
Summary: Record-breaking high coercivity is achieved in Dy-free sintered magnets by separately diffusing Dy70Cu30 and Pr68Cu32 eutectic alloys. The low Dy content sample exhibits a high coercivity of 2.8 T and an excellent temperature coefficient of coercivity. The unique presence of a uniform Dy-rich shell and enriched Pr near the surface of Nd2Fe14B grains strengthens the anisotropy field, resulting in the high coercivity without alloying Dy to the initial magnet.
Article
Nanoscience & Nanotechnology
Kechao Lu, Xiaoqian Bao, Xinfang Song, Yanxin Wang, Minghui Tang, Jiheng Li, Xuexu Gao
Summary: The interface reactions and structure of Pr52.5Tb17.5Cu30, Pr60Tb20Al20, and Pr60Tb10Cu15Al15 alloys with Nd-Fe-B magnets processed at different temperatures were investigated. The Pr60Tb10Cu15Al15 alloy with Al/Cu co-doping showed enhanced Tb diffusion through grain boundaries, leading to thinner Tb-rich grain boundaries and higher coercivity increment. The two-step diffusion process of Pr60Tb10Cu15Al15 resulted in more homogeneous Tb distribution and thinner Tb-rich grain boundaries, achieving 11 kOe coercivity increment with only 0.33 wt% Tb.
SCRIPTA MATERIALIA
(2021)
Article
Metallurgy & Metallurgical Engineering
Cheng Liu, Qun Luo, Qin-Fen Gu, Qian Li, Kuo-Chih Chou
Summary: This study aims to experimentally determine the phase equilibria relationships of Mg-Ni-Y system, focusing on LPSOs, and establish a thermodynamic description. Four types of LPSOs are confirmed and their formation enthalpies are calculated. A new ternary compound, called tau phase, is observed for the first time, which is significant for the design of advanced magnesium-based alloys.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Chemistry, Physical
B. S. Liu, H. X. Li, Y. P. Ren, H. B. Xie, H. C. Pan, M. Jiang, G. W. Qin
Summary: Investigation of phase relationships in the Mg-rich corner of the Mg-Zn-Gd ternary system at 400-475 degrees C reveals changes in equilibrium states, coexistence phenomena, and peritectic eutectic transformations. The compositions of the Z, I, F, and W phases and the solubility of Gd in the alpha-Mg solid solution are significantly affected by the addition of Zn when the phases are in equilibrium.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Composites
David Krzikalla, Jakub Mesicek, Radim Halama, Jiri Hajnys, Marek Pagac, Tomas Cegan, Jana Petru
Summary: This study focused on experimental and numerical examination of the flexural properties of FDM long carbon fibre reinforced composites with polymeric matrix of Onyx through 3-point bending test. The reinforced layer distribution was found to be crucial over the fibre content, with comparable longitudinal material constants but dissimilar shear and transversal constants.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Inorganic & Nuclear
Anitha Anand, M. Manjuladevi, R. K. Veena, V. S. Veena, Yuri S. Koshkid'ko, S. Sagar
Summary: The study investigated the effects of Ti-doping on the structural, magnetic, and magnetocaloric properties of Ti-doped Sm-Sr based manganites. The results showed a decrease in magnetic properties with increasing Ti content, but an increase in working temperature span and a reduction in heat loss associated with magnetic hysteresis.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Anitha Anand, M. Manjuladevi, R. K. Veena, V. S. Veena, Yuri S. Koshkid'ko, S. Sagar
Summary: The study investigates the effect of Ti doping on structural, magnetic, and magnetocaloric properties of Nd-based manganites, finding that N-0.15 exhibits increased Working Temperature Span and decreased magnetic hysteresis loss, making it a potential candidate for low-temperature magnetic refrigeration.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Chemistry, Physical
Ondrej Zivotsky, Katerina Skotnicova, Tomas Cegan, Jan Jurica, Lucie Gembalova, Frantisek Zazimal, Ivo Szurman
Summary: Ternary Mn2FeSi alloy was synthesized through mechanical alloying and its structure and lattice parameters were confirmed. The prepared samples exhibited a heterogeneous magnetic structure consisting of a dominant paramagnetic phase and a weak ferro-/ferrimagnetic contribution.
Article
Crystallography
Jitka Malcharczikova, Katerina Skotnicova, Petr Kawulok, Rostislav Kawulok, Ivo Szurman, Jana Ruzicka
Summary: Ni-Al-Mo based alloys with directionally solidified structure and unique properties are promising for high temperature applications. The compression test results demonstrate their high yield strength and maximal flow stress.
Article
Chemistry, Physical
Yu. S. Koshkid'ko, E. T. Dilmieva, A. P. Kamantsev, J. Cwik, K. Rogacki, A. V. Mashirov, V. V. Khovaylo, C. Salazar Mejiad, M. A. Zagrebin, V. V. Sokolovskiy, V. D. Buchelnikov, P. Ari-Gur, P. Bhale, V. G. Shavrov, V. V. Koledov
Summary: This work focuses on the investigation of the irreversibility of the magnetocaloric effect (MCE) near the magnetostructural phase transition (PT) in Ni-Mn-Ga Heusler alloys. By using direct method and in-situ studies, the width of the irreversible MCE region was determined, and it was found that the presence of residual martensite is the main cause of the irreversible MCE.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Engineering, Electrical & Electronic
Dimitar N. Petrov, N. T. Dang, T. L. Phan, B. W. Lee, J. Cwik, Yu S. Koshkid'ko, T. Manh, H. R. Park, S. C. Yu
Summary: In this study, the magnetic and magnetocaloric behaviors of LiPr(PO3)(4) single crystal were investigated using DC magnetization and heat-capacity measurements. It was found that magnetic order is established at low temperatures and a first-order metamagnetic transition to a ferromagnetic phase occurs under high magnetic fields. The critical field of this transition increases with increasing temperature, possibly related to spin-flop process, spin populations on multiplets, and jj-coupling. After the transition, the maximum magnetic-entropy change follows a power law relationship with the external magnetic field. This study is of significance in understanding the magnetic and magnetocaloric properties of LiPr(PO3)(4).
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Physics, Applied
A. P. Kamantsev, Yu S. Koshkidko, S. Taskaev, V. V. Khovaylo, A. Koshelev, J. Cwik, V. G. Shavrov
Summary: The magnetocaloric effect in samples of the Gd2In compound was studied using the direct method. Both inverse and direct magnetocaloric effects were observed at different temperatures and magnetic fields. The temperature dependence of a first-order metamagnetic phase transition was found to exhibit kinetic arrest.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2022)
Article
Multidisciplinary Sciences
Jacek Cwik, Yurii Koshkidko, Konstantin Nenkov, Evgenia Tereshina-Chitrova, Malgorzata Malecka, Bruno Weise, Karolina Kowalska
Summary: This study examines the magnetocaloric efficiency of rare-earth Laves-phase compounds using Ho1-xErxNi2 as an example and illustrates their potential as components of magnetocaloric composites. The determined regularities in the system's behavior substantiate the possibility of achieving high magnetocaloric potentials in a desired temperature range.
SCIENTIFIC REPORTS
(2022)
Article
Crystallography
Jacek Cwik, Yurii Koshkid'ko, Konstantin Nenkov, Evgenia Tereshina-Chitrova, Bruno Weise, Karolina Kowalska
Summary: The paper presents heat capacity measurements on polycrystalline Tb1-xErxNi2 intermetallic compounds. It was found that the Curie temperatures decrease linearly with the substitution of Tb atoms for Er atoms. The calculated isothermal magnetic entropy and adiabatic temperature changes provide valuable insights into the properties of the compounds.
Article
Materials Science, Multidisciplinary
Fan Li, Dewei Zhao, Jian Liu, Alexander Kamantsev, Elvina Dilmieva, Yury Koshkid'ko, Chunhui Zhu, Li Ma, Congmian Zhen, Denglu Hou
Summary: This study investigates the entropy change and magnetocaloric properties in a Ni50Mn18.5Ga25Cu6.5 Heusler alloy. The structural and magnetic components synergistically contribute to the total entropy change during the magnetostructural transformation. The alloy exhibits a large phase transformation entropy change, with the structural component accounting for the majority. Additionally, the adiabatic temperature change of the alloy under a magnetic field is significant.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Crystallography
Galina Politova, Irina Tereshina, Ioulia Ovchenkova, Abdu-Rahman Aleroev, Yurii Koshkid'ko, Jacek Cwik, Henryk Drulis
Summary: In this study, the magnetocaloric effect in the TbCo2-H system near the Curie temperature was investigated using direct and indirect methods. The magnetic and magnetothermal properties of TbCo2-H with high hydrogen content were examined, and the mechanisms responsible for the change in the Curie temperature were established. The field and temperature dependences of the magnetocaloric effect were analyzed, and the magnetocaloric properties of various systems based on TbCo2 compound were compared. The regularities of the change in the MCE value and the Curie temperature depending on the composition were discovered and discussed.
Article
Materials Science, Multidisciplinary
O. Zivotsky, Y. Jiraskova, J. Bursik, D. Janickovic, J. Cizek
Summary: The structure and magnetic properties of Mn2FeSi alloy, a potential Heusler material, were studied using rapid solidification technology. It was found that the as-prepared Mn2FeSi ribbon exhibited paramagnetism at room temperature and had a cubic structure with a lattice parameter of 0.567 nm. The presence of other phases at low temperatures affected the structural and physical properties of the sample after annealing.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
T. A. Tran, Dimitar N. Petrov, T. L. Phan, B. D. Tu, H. N. Nhat, H. C. Tran, B. Weise, J. Cwik, Yu S. Koshkid'ko, T. V. Manh, T. P. Hoang, N. T. Dang
Summary: We conducted a detailed study on the magnetic behaviors and magnetothermal effects of a single crystal of lithium samarium tetraphosphate, LiSm(PO3)(4). The temperature-dependent magnetization data analysis revealed the establishment of magnetic ordering below T-p, where T-p is the minimum of the dM/dT vs. T curve and varies linearly with the applied field H. The crystal exhibits paramagnetic behavior above T-p, and a coexistence of antiferromagnetic and ferromagnetic interactions is observed due to the couplings of magnetic dipoles and octupoles at the Gamma(7) and Gamma(8) states. Evaluation of the magnetocaloric effect showed an increase in the value of the absolute magnetic-entropy change and adiabatic-temperature change at lower temperatures and higher magnetic field magnitudes.
Article
Physics, Condensed Matter
Y. Jiraskova, J. Bursik, L. Gembalova, J. Cizek, J. Pytlik, O. Zivotsky
Summary: The structural and physical properties of Co2FeZ Heusler alloys were studied and found to be influenced by the choice of Si or Al as the Z element.
PHYSICA B-CONDENSED MATTER
(2024)