Journal of Magnetism and Magnetic Materials最新文献

{"title":"Planar Hall supercurrent and δϕ-shift in the topological Josephson junction","authors":"Morteza Salehi","doi":"10.1016/j.jmmm.2025.172915","DOIUrl":"10.1016/j.jmmm.2025.172915","url":null,"abstract":"<div><div>We theoretically investigate Josephson junctions comprising superconductors and ferromagnets on the surface of three-dimensional topological insulators. We use Bogoliubov-deGennes formalism and show the in-plane magnetization creates a difference between the upward and downward population of Andreev modes and produces a planar Hall supercurrent. Due to the strong spin–orbit interaction of Dirac fermions, bending on the supercurrent imposes a spin transfer torque on the junction. We develop a theory and demonstrate the relation between planar Hall supercurrent and spin transfer torque. The parallel component of in-plane magnetization creates an anomalous supercurrent that can flow even in zero superconducting phase difference and make <span><math><mrow><mi>δ</mi><mi>ϕ</mi></mrow></math></span>-junction. We show in some range, <span><math><mrow><mi>π</mi><mo>/</mo><mn>2</mn><mi>d</mi><mo>≤</mo><msub><mrow><mi>m</mi></mrow><mrow><mi>y</mi></mrow></msub><mo>≤</mo><mi>π</mi><mo>/</mo><mi>d</mi></mrow></math></span>, there is a <span><math><mi>π</mi></math></span> shift in the Josephson supercurrent. This research advances our understanding of quantum transport in 3DTIs and highlights their potential in emerging quantum technologies.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"621 ","pages":"Article 172915"},"PeriodicalIF":2.5,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562328","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}

{"title":"Electronic and magnetic properties of quantum ring with two off-center donor atoms","authors":"A. Bakdid ,&nbsp;M. Hbibi ,&nbsp;S. Chouef ,&nbsp;R. Boussetta ,&nbsp;A. El Moussaouy ,&nbsp;O. Mommadi ,&nbsp;C.A. Duque","doi":"10.1016/j.jmmm.2025.172891","DOIUrl":"10.1016/j.jmmm.2025.172891","url":null,"abstract":"<div><div>This study examines the impact of two hydrogenic donors impurities on the electronic properties of Quantum Ring with Square or Rectangular Cross-Sections (QRSRCS). We considered two hydrogenic off-center donors impurities into a GaAs QRSRCS and explored their interaction with an electron confined within the structure. Using the effective mass approximation and the finite difference method, we calculated the electronic energy, the binding energy, the distance between the electron and the impurities, and the diamagnetic susceptibility for various geometrical configurations of the QRSRCS and the impurities. The results show that the presence of impurities reduces the ground state energy of the confined electron, significantly modifying the probability distribution and affecting the electronic properties of the QRSRCS. In addition, the interaction between the impurities reduces the stability of our nanosystem. The shape of the QRSRCS strongly influences these effects, the distance between the impurities and the electron, and the interaction between the impurities themselves. The study of these effects as a function of various geometrical parameters of the QRSRCS offers perspectives for the manipulation of electronic properties in quantum devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"621 ","pages":"Article 172891"},"PeriodicalIF":2.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550028","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}

{"title":"Research on demagnetization characteristics of eddy current brake under impact load","authors":"Tiantian Liu,&nbsp;Lei Li,&nbsp;Liqun Wang,&nbsp;Peng Peng,&nbsp;Zongfan Wang,&nbsp;Guolai Yang","doi":"10.1016/j.jmmm.2025.172935","DOIUrl":"10.1016/j.jmmm.2025.172935","url":null,"abstract":"<div><div>In this paper, eddy current brake are applied to artillery, and three layouts of it on large-caliber artillery are introduced. A demagnetization model for neodymium iron boron (NdFeB) permanent magnets under impact was proposed based on experimental data and its numerical calculation model is established by joint simulation. A surrogate model for the impact demagnetization model was trained using a Radial Basis Function (RBF) neural network and combined with a particle swarm optimization algorithm to identify the key parameters of the permanent magnet impact demagnetization model. Based on the dynamics of artillery firing, numerical calculation models for electromagnetic forces were developed for different artillery structures, and the electromagnetic forces generated by each structure were calculated. Fine discrete modeling was conducted on the three types of artillery structures, and Abaqus software was utilized to quantitatively calculate the impact demagnetization for each structure. The demagnetization behavior of eddy current brakes under different configurations is analyzed and compared and the reliability of three structural designs is verified. It proposes the addition of a protective cover to Structure II to reduce the area of irreversible demagnetization and validates the feasibility of this approach.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"621 ","pages":"Article 172935"},"PeriodicalIF":2.5,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550502","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}

{"title":"Error compensation and precise tracking control of magnetic miniature swimmers via inverse modeling with deep neural networks","authors":"Hongbiao Xiang ,&nbsp;Yanming Cao ,&nbsp;Xu Cheng ,&nbsp;Xianghong Zhao ,&nbsp;Jiahao Lu ,&nbsp;Yuexin Zhang ,&nbsp;Lu Yang ,&nbsp;Sen Zhang ,&nbsp;Shoujun Wang ,&nbsp;Mian Zhang","doi":"10.1016/j.jmmm.2025.172936","DOIUrl":"10.1016/j.jmmm.2025.172936","url":null,"abstract":"<div><div>Magnetic miniature swimmers hold significant potential for applications in biomedical and other fields. However, their precise control remains a major challenge due to fabrication imperfections and magnetic field inhomogeneities. In this paper, we designed a small-size swimmer composed of magnetoelastic composite materials, capable of swimming on liquid surfaces. To address the deviation between the desired angle and the actual swimmer angle, and to improve motion control accuracy, an inverse modeling approach with deep neural networks (IMDNN) was proposed for error compensation. In open-loop experiments, IMDNN compensation reduced angle error and position error by 75.2 % and 85.9 %, respectively. When integrated into a closed-loop control framework combining the line-of-sight (LOS) navigation method and PID control, IMDNN further enhanced trajectory tracking precision and disturbance rejection. Closed-loop path tracking experiments demonstrated reductions of 67.7 % and 77.6 % in angle error and position error, respectively, compared to control without compensation. The results show that the proposed error compensation method significantly reduces path tracking errors, providing a novel strategy for the precise control of miniature swimmers. This method offers a promising solution for applications in biomedical micromanipulation and targeted drug delivery fields.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"621 ","pages":"Article 172936"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550027","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}

{"title":"Trajectory analysis of single magnetic bead under elliptical cylindrical magnet and rotating field","authors":"Ruohan Li ,&nbsp;Jiajia Sun ,&nbsp;Zongqian Shi ,&nbsp;Ruixuan Zhao ,&nbsp;Xiaofeng Liu ,&nbsp;Shumin Xin ,&nbsp;Nan Wang ,&nbsp;Xinxiao Shui ,&nbsp;Wanyi Du ,&nbsp;Kai Wu","doi":"10.1016/j.jmmm.2025.172934","DOIUrl":"10.1016/j.jmmm.2025.172934","url":null,"abstract":"<div><div>This paper proposes an analytical method based on the equivalent magnetic charge approach to accurately analyze the magnetic field and force under an elliptical cylindrical magnet and a rotating field. This method minimizes the impact of mesh size on accuracy, improving computational efficiency. Moreover, a Lagrangian-Eulerian model is proposed to predict the magnetic bead trajectory under an elliptical cylindrical magnet combined with a rotating magnetic field, taking into account the coupling between the magnetic beads and the fluid. The influence of magnet geometry and rotating field frequency on the translational and rotational trajectory of a single magnetic bead is investigated. This work demonstrates the feasibility of using the Lagrangian-Eulerian model to analyze magnetic bead trajectories under specific soft-magnetic element geometries, providing a robust theoretical foundation for optimizing the design of the magnetophoretic circuits and enhancing control over the motion of single magnetic beads and bead-labeled cells in magnetophoretic circuits.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"620 ","pages":"Article 172934"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534650","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}

{"title":"On the magnetic and magnetocaloric features of La2/3Sr1/3MnO3-based materials: From bulk to nano","authors":"O. Chdil ,&nbsp;M.A. Eskandari ,&nbsp;N. Brahiti ,&nbsp;S. Ait Jmal ,&nbsp;J.P. Salvestrini ,&nbsp;P. Fournier ,&nbsp;M. Balli","doi":"10.1016/j.jmmm.2025.172898","DOIUrl":"10.1016/j.jmmm.2025.172898","url":null,"abstract":"<div><div>The La<span><math><msub><mrow></mrow><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msub></math></span>Sr<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>3</mn></mrow></msub></math></span>MnO₃ manganite exhibits interesting levels of magnetocaloric effect at relatively high temperatures because of the phase transition from the ferromagnetic to paramagnetic state occurring at its Curie temperature T<span><math><mrow><msub><mrow></mrow><mrow><mtext>c</mtext></mrow></msub><mo>=</mo><mn>370</mn></mrow></math></span> K. Herein, the possibility of tailoring its magnetic and magnetocaloric properties over the practical temperature range going from 300 K to 370 K is investigated by using both bulk and nano approaches. In this way, the reduction of La<span><math><msub><mrow></mrow><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msub></math></span>Sr<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>3</mn></mrow></msub></math></span>MnO₃ size to monolayers of 25 to 30 nm grown on LSAT substrates enables us to decrease T<span><math><msub><mrow></mrow><mrow><mtext>c</mtext></mrow></msub></math></span> from 370 K to 355 K which is associated with a significant decrease in the magnetocaloric effect. However, the introduction of only 5% of copper oxide as a secondary phase in the bulk La<span><math><msub><mrow></mrow><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msub></math></span>Sr<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>3</mn></mrow></msub></math></span>MnO₃ matrix shifts T<span><math><msub><mrow></mrow><mrow><mtext>c</mtext></mrow></msub></math></span> to about 348 K without affecting the magnetocaloric potential of the pristine compound.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"621 ","pages":"Article 172898"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562327","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}

{"title":"Holmium-substituted magnesium ferrites: Structural, magnetic, and electrical transport properties","authors":"S. Karimunnesa ,&nbsp;M.R. Hasan ,&nbsp;F. Alam ,&nbsp;M.N.I. Khan","doi":"10.1016/j.jmmm.2025.172917","DOIUrl":"10.1016/j.jmmm.2025.172917","url":null,"abstract":"<div><div>Magnesium ferrites with holmium substitution were produced utilizing the solid-state reaction process. The nominal composition of the ferrites is MgFe_2-xHo_xO₄, where x ranges from 0.0 to 0.20 at intervals of 0.05. All specimens under investigation were sintered at 1200 °C for three hours. X-ray diffraction patterns of the studied samples were analyzed, and a cubic spinel structure in a single phase was confirmed. The bulk density, lattice constant, and X-ray all climb linearly with increasing holmium content, while sample porosity decreases. Their ionic radii were used to discuss the increase in lattice parameters that occurred when Ho³⁺ was substituted for Fe³⁺. Inhomogeneous grain size distributions from their electron micrographs were observed in the specimens. As Ho³⁺ substitution increases, the initial permeability of each sample increases in tandem with its density and particle size. Rare earth Ho³⁺ has a greater impact on the magnetic properties of MgFe_2-xHo_xO₄, which results in the growth of saturation magnetization up to x  = 0.1, but coercivity and anisotropy constant decrease linearly in all the studied samples. Low values of coercivity approve the softness of ferrites that is established from the narrow M−H loops. As Ho³⁺ substitution increases, the Curie temperature drops linearly, indicating a weakening of the A-B exchange interaction is supported by a rise in the lattice constant. The rapid decrease in temperature-dependent initial permeability in ferrite specimens indicates homogeneity and single-phase growth, as confirmed by X-ray diffraction. In every one of the detailed samples, the loss factor and dielectric constant drop sharply with increasing frequency and almost flatten out at very high frequencies. Generally, ferrite materials have low resistivity and dielectric constants. But with Ho³⁺ substitution, the resistivity of MgFe_2-xHo_xO₄ improved up to x  = 0.10 compared with the other samples, which is encouraging for multilayer ceramic capacitor and multilayer chip inductor applications.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"620 ","pages":"Article 172917"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534651","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}

{"title":"Electric field control of magnetic coercivity in epitaxial FeGa/BaTiO3 heterostructures","authors":"Minh-Anh Tran ,&nbsp;Viet-Dung Tran ,&nbsp;Thi Huong Nguyen ,&nbsp;Nguyen Viet Chien ,&nbsp;Van Quang Nguyen ,&nbsp;Nguyen Cao Khang ,&nbsp;Chanyong Hwang ,&nbsp;Sunglae Cho","doi":"10.1016/j.jmmm.2025.172851","DOIUrl":"10.1016/j.jmmm.2025.172851","url":null,"abstract":"<div><div>We investigate the electric field control of magnetism in an epitaxial Fe₈₀Ga₂₀/BaTiO₃ (FeGa/BTO) heterostructures. The as-grown FeGa film exhibits biaxial magnetic anisotropy, with the magnetic easy axis aligned along the FeGa[100] and [010] directions. When an out-of-plane electric field (E) ranging from 0 to 14 kV/cm is applied to the BTO substrate, the coercivity of the film measured along the magnetic easy axis decreases from 145 Oe to 102 Oe, corresponding to an approximate 30 % reduction. Notably, the squareness of the hysteresis loop remains constant at M_R/M_S ∼ 1, suggesting that the magnetic anisotropy remains largely unchanged while the magnetic moment of the film may be modified. This observation is likely influenced by the strain introduced during the domain switching process of the BTO, which is efficiently transferred to the epitaxial FeGa film through magnetoelectric coupling at the FeGa/BTO interface. Additionally, the variation in the magnetic moment could be related to the displacement of atoms at the interface during the polarization rotation of the BTO under the applied electric field. Further studies are required to isolate and quantify the contributions of these mechanisms.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"620 ","pages":"Article 172851"},"PeriodicalIF":2.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534649","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}

{"title":"Study on magnetic circuit design and energy efficiency ratio of comb-type disk magnetorheological brakes","authors":"YuXin Xia,&nbsp;Xiaolong Yang,&nbsp;Zhiqiang Cao","doi":"10.1016/j.jmmm.2025.172913","DOIUrl":"10.1016/j.jmmm.2025.172913","url":null,"abstract":"<div><div>At present, most of the magnetorheological brakes(MRBs) have magnetic leakage phenomenon, so that there will be a certain loss after the MRB is energized with current, which makes the actual output braking torque much smaller than the theoretical output braking torque obtained from the calculation, and the energy efficiency is relatively low. In this paper, comb-type disk magnetorheological brake(CTD-MRB) with two sub-coils is presented and designed, which changes the overall coil arrangement structure of the brake. Through electromagnetic field numerical simulation and experimental analysis, the actual braking torque of the main and auxiliary coils under different working modes is compared, and the corresponding energy efficiency ratios under various working modes are found.. The results show that the improved structure can improve the braking torque by 4 %, and the braking torque can reach 360 N·m, but the energy efficiency ratio is reduced by 5.3 %.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"620 ","pages":"Article 172913"},"PeriodicalIF":2.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534648","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}

{"title":"Corrosion behavior and magnetocaloric effect of La0.8Ce0.2Fe11.51Mn0.19Si1.3Hy plates with plasma sprayed Al powder coating","authors":"Juan Cheng ,&nbsp;Caiyin You ,&nbsp;Na Tian ,&nbsp;Lei Gao ,&nbsp;Yaru Guo ,&nbsp;Boyu Song ,&nbsp;Hao Pei ,&nbsp;Peiyu Jin","doi":"10.1016/j.jmmm.2025.172925","DOIUrl":"10.1016/j.jmmm.2025.172925","url":null,"abstract":"<div><div>The corrosion resistance of La(Fe, Si)₁₃H<em>_y</em> alloy in flowing water is a noteworthy issue relevant to the practical application since water is usually used as a heat transfer medium in magnetic refrigerator. In this work, it was found that the corrosion of the La_0.8Ce_0.2Fe_11.51Mn_0.19Si_1.3H<em>_y</em> alloy becomes more severe as the temperature and the flow rate increase. But the corrosion resistance of the alloy was highly improved through a coating with Al by plasma spray technique without the significant loss of the magnetic properties. Upon coating of 35 µm Al layers the corrosion potential E_corr increases to −334 mV from −533 mV and the corrosion current density I_corr decreases to 4.56 × 10⁻⁶ A/cm² from 1.19 × 10⁻⁵ A/cm². The plate coated with Al did not present any cracks after 2 × 10⁴ magnetic field cycles with −<em>ΔS_m</em> of 12.3 J/kg∙K, E_corr of –333 mV and I_corr of 4.85 × 10⁻⁶ A/cm².</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"620 ","pages":"Article 172925"},"PeriodicalIF":2.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534652","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}