Journal of Magnetism and Magnetic Materials最新文献_第3页

Magnetization of a classical XY spin trimer in a coplanar magnetic field 经典XY自旋三聚体在共面磁场中的磁化

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-19 DOI: 10.1016/j.jmmm.2025.173495

Orion Ciftja , Olta Çakaj

{"title":"Magnetization of a classical XY spin trimer in a coplanar magnetic field","authors":"Orion Ciftja , Olta Çakaj","doi":"10.1016/j.jmmm.2025.173495","DOIUrl":"10.1016/j.jmmm.2025.173495","url":null,"abstract":"<div><div>Advances in molecular magnetism have led to the realization of nanomagnets consisting of clusters of a small number of spins. Many times single quantum spins combine into an entity with a relatively large spin which, in turn, is coupled to similar peer entities. For this condition, one can see the spin vector operator as a classical Heisenberg spin vector of unit length. In systems where interactions favor alignment in the plane, such as in ultracold atoms in optical lattices or planar magnetic materials with anisotropic exchange coupling, clusters of spins with large-spin values can be viewed as classical Heisenberg XY spins. In this work we calculate exactly the magnetic properties of a trimer of <span><math><mrow><mi>N</mi><mo>=</mo><mn>3</mn></mrow></math></span> classical Heisenberg XY spins in a coplanar magnetic field. Presence of a magnetic field makes this problem impossible to solve by standard transfer matrix methods used for decades. However, a different mathematical approach whose idea is the introduction of auxiliary spin variables into the starting expression of the partition function leads to interesting compact exact results. We illustrate the application of the method by calculating the total magnetic moment (spin) for the case of a classical XY spin trimer system in a coplanar magnetic field at arbitrary values of the magnetic field and arbitrary temperatures.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173495"},"PeriodicalIF":3.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ferrofluid-based magnetic patterning: Labyrinthine and spikes structures stabilized by UV crosslinking 基于铁磁流体的磁图型：由UV交联稳定的迷宫和尖峰结构

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-18 DOI: 10.1016/j.jmmm.2025.173509

Laura M. Sanchez

{"title":"Ferrofluid-based magnetic patterning: Labyrinthine and spikes structures stabilized by UV crosslinking","authors":"Laura M. Sanchez","doi":"10.1016/j.jmmm.2025.173509","DOIUrl":"10.1016/j.jmmm.2025.173509","url":null,"abstract":"<div><div>The pattern formation in ferrofluids because of the application of an external magnetic stimulus has been experimentally and numerically studied for decades. However, most of these studies have been conducted considering hydrophobic or super-hydrophobic substrates surfaces, and the obtained patterns were not permanent. In this research a hydrophilic glass surface and a Fe<sub>2</sub>O<sub>3</sub>-based ferrofluid system were used. First, the influence of the magnetic suspension concentration on the obtained pattern was studied. Then, by fixing the magnetic nanoparticles concentration the effect of varying the external magnetic strength was considered. Depending on the working conditions, labyrinthine-like and spikes patterns were obtained. The critical parameters to switch from one to the other architecture were determined and discussed. Furthermore, each obtained pattern was permanently fixed through the employment of UV-irradiation thanks to the simple addition of an epoxy photoresist reactant to the initial ferrofluid mixture. The results presented are promising for the development of new and more complex materials.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173509"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on weak magnetic detection of coating layer pipelines based on adjustable excitation 基于可调励磁的涂层管道弱磁检测研究

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-17 DOI: 10.1016/j.jmmm.2025.173511

Xiaohui Yang , Muhao Yang , Yipeng Chen , Jialong Jiang , Sihang Zhu , Shuai Li , Liang Ge

{"title":"Research on weak magnetic detection of coating layer pipelines based on adjustable excitation","authors":"Xiaohui Yang , Muhao Yang , Yipeng Chen , Jialong Jiang , Sihang Zhu , Shuai Li , Liang Ge","doi":"10.1016/j.jmmm.2025.173511","DOIUrl":"10.1016/j.jmmm.2025.173511","url":null,"abstract":"<div><div>To explore an effective nondestructive testing method for coating layer pipelines, a weak magnetic detection method with adjustable excitation is proposed in this paper. Based on the Jiles-Atherton (J-A) magneto-mechanical coupling model, the optimal stress-sensitive excitation magnetic field is set at 600 A·m<sup>−1</sup>. The electro-magnetic-mechanical multiphysics coupling simulations are conducted to investigate the variations of magnetic signal in excitation magnetic field. To achieve optimal excitation, the excitation current should be adjusted according to the coating thickness, following a quadratic relationship. Two characteristic parameters have been introduced to quantitatively analyze the effect of the excitation magnetic field on the weak magnetic signal. The characteristic parameter <em>S</em><sub><em>t</em></sub> under the excitation magnetic field is approximately 20 times higher than in the geomagnetic field. The influence of defect size, load magnitude, and coating layer thickness on the magnetic signals are respectively discussed. The experimental results of weak magnetic detection on 20# steel specimens align well with the simulation results. This indicates that the excitation magnetic field can effectively enhance the magnetic signal intensity and improve the sensitivity of defect detection. The results provide a theoretical foundation for the application of adjustable weak magnetic excitation methods in the inspection of coated pipelines.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173511"},"PeriodicalIF":3.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145098342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Large room temperature magnetocaloric effect in a low-cost (MnNiSi)1-x(FeCoSi)x system 低成本（MnNiSi）1-x(FeCoSi)x系统中的大室温磁热效应

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-17 DOI: 10.1016/j.jmmm.2025.173512

Tao Wang , Haicheng Xuan , Xingfa Zhu , Fenghua Chen , Junwei Qiao , Long Cheng

引用次数: 0

Controlling perpendicular magnetic anisotropy and damping in thulium iron garnet films by strain engineering 应变工程控制铥铁石榴石薄膜的垂直磁各向异性和阻尼

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-17 DOI: 10.1016/j.jmmm.2025.173513

Zimu Li , Tengfei Zhang , Quwen Wang , Qian Zhao , Feng Li , Yixin Fan , Chenbo Zhao , Jianbo Wang , Qingfang Liu , Guoqiang Yu , Jinwu Wei

{"title":"Controlling perpendicular magnetic anisotropy and damping in thulium iron garnet films by strain engineering","authors":"Zimu Li , Tengfei Zhang , Quwen Wang , Qian Zhao , Feng Li , Yixin Fan , Chenbo Zhao , Jianbo Wang , Qingfang Liu , Guoqiang Yu , Jinwu Wei","doi":"10.1016/j.jmmm.2025.173513","DOIUrl":"10.1016/j.jmmm.2025.173513","url":null,"abstract":"<div><div>Controlling the magnetic properties of rare-earth iron garnet films is important for applications in spintronics and magnonics devices. Here, we prepared the epitaxial thulium iron garnet (TmIG) thin films by sputtering on (111)-oriented garnet substrates. An in-plane tensile strain is induced by the lattice mismatch between TmIG and substrate, and the magnitudes of tensile strain in TmIG films can be tuned through the film thickness. Static magnetic properties show a significant perpendicular magnetic anisotropy of TmIG films. Ferromagnetic resonance measurement was employed to characterize the high-frequency magnetic properties of TmIG films. The results show that the first- and second-order magnetic anisotropy, gyromagnetic ratio and Gilbert damping parameter strongly depend on the tensile strain. The Gilbert damping is about 8.8 × 10<sup>−3</sup> for the 50-nm TmIG film. In addition, we also studied the high-frequency magnetic properties at low temperatures of the TmIG films. This work offers a valuable insight for the strain engineering design and demonstrates the potential of TmIG thin films as a promising candidate for applications in spintronic and magnonic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173513"},"PeriodicalIF":3.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Grain boundary diffusion effects of heavy-rare-earth-free alloys with multi-elements in sintered Nd-Fe-B magnets 多元素重稀土合金在烧结Nd-Fe-B磁体中的晶界扩散效应

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-16 DOI: 10.1016/j.jmmm.2025.173508

Shuai Cao , Chenglong Li , Zhi Jia , Zhiwei Xiong , Shuangyu Zheng , Guangfei Ding , Xiaodong Fan , Shuai Guo , Bo Zheng , Renjie Chen , Aru Yan

{"title":"Grain boundary diffusion effects of heavy-rare-earth-free alloys with multi-elements in sintered Nd-Fe-B magnets","authors":"Shuai Cao , Chenglong Li , Zhi Jia , Zhiwei Xiong , Shuangyu Zheng , Guangfei Ding , Xiaodong Fan , Shuai Guo , Bo Zheng , Renjie Chen , Aru Yan","doi":"10.1016/j.jmmm.2025.173508","DOIUrl":"10.1016/j.jmmm.2025.173508","url":null,"abstract":"<div><div>Heavy-rare-earth-free Pr<sub>60</sub>Fe<sub>10</sub>Cu<sub>5</sub>Al<sub>10</sub>Ga<sub>15</sub> (at.%) alloy powders with certain ferromagnetism were designed and prepared as the diffusion sources to conduct grain boundary diffusion (GBD) on commercial N55 Nd-Fe-B sintered magnets, in which the ferromagnetic alloy powders had completed the attachment on the surface of the magnets by a magnetic attraction deposition method before heat-treatments. The coercivity of the magnet increased significantly from the original 14.78 kOe to 22.80 kOe after completing the GBD process, accompanied by the noticeable declines both in remanence and magnetic energy product. Microstructure and muti-element distribution analyses showed that the significant improvement in coercivity was mainly attribute to the excellent diffusion effects of Pr-Fe-Cu-Al-Ga alloys in GBD, and the apparent networks of RE-rich grain boundaries had formed and spanned across considerable areas both below the pole and side surface of the magnet. Specially, some typical continuous and penetrating grain boundaries mainly vertical to the c-axis had been formed, that could be closely related to both the intrinsic anisotropy of Nd-Fe-B magnet and the generation of 6:14 type phases during annealing process, based on the detailed microstructural and line-scan analyses. In addition, dynamic domain evolution analyses indicating the positive effect of Pr-Fe-Cu-Al-Ga diffusion on anti-demagnetization. This work provided a foundation for the development of heavy-rare-earth-free diffusion sources also with their corresponding GBD technology in Nd-Fe-B sintered magnets.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"631 ","pages":"Article 173508"},"PeriodicalIF":3.0,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-temperature superconducting magnetic levitation system with V-shaped permanent magnet guideway: Experiment and its parameter optimization v型永磁导轨高温超导磁悬浮系统实验及参数优化

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-15 DOI: 10.1016/j.jmmm.2025.173507

Jie Zheng, Lingfeng Gao, Wuyang Lei, Zigang Deng

{"title":"High-temperature superconducting magnetic levitation system with V-shaped permanent magnet guideway: Experiment and its parameter optimization","authors":"Jie Zheng, Lingfeng Gao, Wuyang Lei, Zigang Deng","doi":"10.1016/j.jmmm.2025.173507","DOIUrl":"10.1016/j.jmmm.2025.173507","url":null,"abstract":"<div><div>As the external magnetic field source in high-temperature superconducting (HTS) maglev systems, the permanent magnet guideway (PMG) is crucial in determining the levitation and guidance performance. The PMG structure especially has a significant impact on levitation and guidance performance. The previous simulation results have shown that the V-shaped PMG can significantly improve the guidance force and increase the levitation force of the HTS maglev system compared to the horizontal PMG. However, experiments were not conducted to validate the simulation results in the previous study. Building upon earlier work, this study designs and fabricates a V-shaped PMG and compares it with a horizontal PMG. The experimental results verify that the V-shaped PMG has better levitation performance than the horizontal PMG. Moreover, this paper explains why using a V-shaped PMG can improve the levitation and guidance performance and explores the effects of the permanent magnet array and the gap between the two sides of the V-shaped PMG on the levitation and guidance forces. The results indicate that the symmetric permanent magnet array and reducing the gap between the V-shaped PMG can improve the levitation performance to some extent. This study verified the feasibility of applying the V-shaped PMG and promoting the engineering application of the next-generation HTS maglev system.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"631 ","pages":"Article 173507"},"PeriodicalIF":3.0,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiphysics modelling of magnetic Curie point materials: Application to thermal self-regulation during induction heating 磁性居里点材料的多物理场建模：在感应加热过程中热自调节中的应用

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-15 DOI: 10.1016/j.jmmm.2025.173496

Hakim Oueslati , Guillaume Wasselynck , Didier Trichet , Simon Morville

{"title":"Multiphysics modelling of magnetic Curie point materials: Application to thermal self-regulation during induction heating","authors":"Hakim Oueslati , Guillaume Wasselynck , Didier Trichet , Simon Morville","doi":"10.1016/j.jmmm.2025.173496","DOIUrl":"10.1016/j.jmmm.2025.173496","url":null,"abstract":"<div><div>Controlled Curie point materials are considered innovative due to their property of abrupt magnetic extinction when their temperature exceeds a specific threshold. This property could be used to make them very suitable for a variety of industrial processes that require temperature self-regulation. The use of these materials in magnetic induction heating may allow the power transfer to be greatly reduced at the Curie point, ensuring precise control of the heating process. However, recent developments have enabled the design of customisable materials, where the Curie threshold can be precisely adjusted during the manufacturing process in a range from ambient temperature to several hundred degrees. This tunability is commonly achieved in FeNi-based alloys, where the Curie temperature is controlled by adjusting the composition ratio of nickel and iron. Other alloying elements, such as aluminium or rare earth metals, can also be incorporated to further modify the magnetic and thermal properties. Therefore, designers need modelling tools to handle these phenomena. In this paper, a two-dimensional coupled electromagnetic and thermal model for the induction heating of magnetic materials with a low Curie point temperature is developed to validate the proof of concept.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"631 ","pages":"Article 173496"},"PeriodicalIF":3.0,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Extended dipole approximation of a ship induced magnetic signature modeled by means of a hollow cylinder 用空心圆柱体模拟船舶感应磁信号的扩展偶极近似

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-14 DOI: 10.1016/j.jmmm.2025.173484

Roberto Zivieri, Vincenzo Crupi

引用次数: 0

Hubbard dimer in near-surface magnetic and electric field: Magneto-electro-spatial phase transitions 近地表磁场和电场中的哈伯德二聚体：磁电空间相变

IF 3 3区材料科学

Journal of Magnetism and Magnetic Materials Pub Date : 2025-09-12 DOI: 10.1016/j.jmmm.2025.173482

K. Szałowski, T. Balcerzak

引用次数: 0