Journal of Magnetism and Magnetic Materials最新文献

{"title":"Magneto-dielectric composites synthesized using industrial waste","authors":"Sunil Kumar ,&nbsp;Shiffali Middha ,&nbsp;Sajan Masih ,&nbsp;Arshdeep Kaur ,&nbsp;Jaswinder Pal ,&nbsp;Norah Alhokbany ,&nbsp;Jahangeer Ahmed ,&nbsp;Gurpreet Singh ,&nbsp;López-García ,&nbsp;Satvir Singh ,&nbsp;Nitin Tandon ,&nbsp;Indu Sharma ,&nbsp;Arvind Kumar Sharma ,&nbsp;Anupinder Singh","doi":"10.1016/j.jmmm.2025.173306","DOIUrl":"10.1016/j.jmmm.2025.173306","url":null,"abstract":"<div><div>Coal Ash (CA) is an industrial waste procured from brick klin as waste obtained during the firing of raw bricks using rock coal, whereas BaTiO₃ (BT) &amp; KNaNbO₃ (KNN) well well-known ferroelectric perovskites synthesized in the laboratory using conventional solid solution approach. Multiferroic composites of _0.5Coal Ash-_0.5BaTiO₃ &amp; _0.5Coal Ash-_0.5KNaNbO₃ have been synthesized by mechanical mixing approach of Coal Ash collected from brick clan and as-synthesized BaTiO₃ &amp; KNaNbO₃. Structural phases present in Coal Ash have been analyzed according to metal ions confirmed from energy dispersive X-ray spectroscopy whereas diffraction peaks correspond to the tetragonal phase of BaTiO₃ and monoclinic phase of KNaNbO₃ in prepared composites of CA &amp; BT, KNN confirmed the successful synthesis of ceramic composites mentioned above. Morphological analysis has been carried out by scanning the surface of sintered pellets using an electron microscope, whereas energy dispersive spectroscopy (EDS) gives details of different elements present in studied samples. S-shaped magnetic hysteresis (Magnetization vs. Magnetic field hysteresis) manifests magnetic ordering in composites of Coal Ash &amp; non-magnetic ferroelectric BT &amp; KNN. The magnetic behavior of ceramic composites mainly due to different magnetic particles were present during coal combustion confirmed from x-ray diffraction analysis as well as presence of Fe metal ion confirmed from EDS spectroscopy. ε’ &amp; ε“ and σ_ac vs frequency evident for enhanced dielectric and conducting properties of multiferroic composites by processing Coal Ash with BT &amp; KNN and ‘α’ (Obtained from Fitting of Dielectric data) determined the deviation in dielectric behavior of ceramic composites from normal Debye behavior. The change in the value of dielectric permittivity in the presence and absence of a magnetic field stamped for the presence of magneto-dielectric response in _0.5Coal Ash-_0.5BaTiO₃ &amp; _0.5Coal Ash-_0.5KNaNbO₃ multiferroic composites.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173306"},"PeriodicalIF":2.5,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490467","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":"Steady high-frequency antiskyrmion oscillator with anisotropic Dzyaloshinskii-Moriya interaction","authors":"Xuefeng Wu","doi":"10.1016/j.jmmm.2025.173324","DOIUrl":"10.1016/j.jmmm.2025.173324","url":null,"abstract":"<div><div>Magnetic skyrmions have garnered significant interest in recent years due to their potential applications in spintronic devices, such as spin-torque nano-oscillators (STNOs) and racetrack memory. However, the development of skyrmion-based STNOs has been hindered by their sub-GHz operational frequencies and propensity for annihilation under high current densities. In this study, stable antiskyrmion auto-oscillations in nanodisk geometries driven by spinpolarized currents enabled by anisotropic Dzyaloshinskii-Moriya interaction (DMI) were demonstrated. Through systematic comparisons of isotropic and anisotropic DMI systems, we uncover distinct topological stabilization mechanisms and current–density-dependent dynamics. At intermediate current densities (10–15 × 10¹¹ A·m⁻²), antiskyrmions exhibit a hybrid breathing-rotational mode, achieving oscillation frequencies of 9.66 GHz (in-plane) and 38.8 GHz (out-of-plane), with a robust frequency ratio of 3.9–4.1. Notably, antiskyrmions sustain current densities up to 400 % of the annihilation thresholds for conventional skyrmions, attributed to their unique chirality-dependent force equilibration. The tangential velocity of antiskyrmions reaches 587 m/s at 15 × 10¹¹ A·m⁻², governed by competing dependencies on current density and size contraction. These findings establish antiskyrmion-based STNOs as promising platforms for high-frequency, low-power spintronic applications, overcoming critical limitations of conventional skyrmion systems.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173324"},"PeriodicalIF":2.5,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517952","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":"Impact of charge stripes on magnetization processes in rare-earth tetraborides","authors":"Pavol Farkašovský","doi":"10.1016/j.jmmm.2025.173284","DOIUrl":"10.1016/j.jmmm.2025.173284","url":null,"abstract":"<div><div>We examine the impact of charge stripes on magnetization processes in rare-earth tetraborides within a complex model which takes into account the electron and spin subsystem as well as the coupling (of the Ising type) between both subsystems. The charge stripes in this model are induced by adding the phenomenological, spatially varying local potential <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>. Our assumption is based on a comparison of structural and electronic similarities between the rare-earth tetraborides and rare-earth hexaborides/dodecaborides, where such charge stripes (as a consequence of the Jahn–Teller effect) were experimentally observed. It is shown that the form and intensity of local potential <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> (the type of charge stripes) have dramatic impact on the stability of individual plateaus on magnetization curves. The largest effects have been observed for the periodic potential forming the full charge stripes alternating with chessboard charge stripes. This type of charge ordering leads to magnetization curves with extremely simple structure consisting of only two main magnetization plateaus with fractional magnetization m=1/2 and m=1/3, the stability regions of which depend strongly on the model parameters. It is shown that with increasing intensity of local potential <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> the 1/2 plateau (1/3 plateau) is generally stabilized (suppressed) and this effect is further enhanced by increasing spin-electron coupling leading to total disappearance of the 1/3 plateau, exactly as is observed in TmB<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> and ErB<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>. It should be noted that although charge stripes are introduced here ad hoc, the fact that our picture of magnetization processes is fully consistent with experimental measurements in TmB<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> and ErB<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> indicates that this assumption is reasonable and could serve as motivation for experimental physicists to find such a type of charge ordering in these materials.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173284"},"PeriodicalIF":2.5,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490466","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":"Electron spin resonance study of the van der Waals ferromagnet Fe5GeTe2","authors":"Yang Yang ,&nbsp;Fanying Meng ,&nbsp;Wei Liu ,&nbsp;Jingxin Li ,&nbsp;Jing Zhang ,&nbsp;Jiyu Fan ,&nbsp;Chunlan Ma ,&nbsp;Min Ge ,&nbsp;Li Pi ,&nbsp;Zhe Qu ,&nbsp;Lei Zhang","doi":"10.1016/j.jmmm.2025.173251","DOIUrl":"10.1016/j.jmmm.2025.173251","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The van der Waals (vdW) material Fe&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;GeTe&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; is a promising candidate for spintronic applications due to its high Curie temperature (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) and easily controllable properties. In this study, we thoroughly investigate the magnetic anisotropy of Fe&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;GeTe&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; single crystals using magnetization and electron spin resonance (ESR) techniques. We find that the magnetization for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; is stronger than that for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; below &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;100 K, exhibiting a weak easy-plane anisotropy (EPA). This EPA is significantly enhanced in the temperature range of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, indicating an enhanced EPA effect. Meanwhile, the ESR spectra show weak intensity below &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; while significantly anisotropic signals are observed in the enhanced EPA region, with stronger ESR intensity for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; compared to that for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. The resonance fields (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; display opposite trends. The resonance field &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; shifts toward lower fields, while &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; moves toward higher fields upon cooling. This contrary trends of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; are attributed to the effects of ","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173251"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471055","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":"Magnetic anisotropy of Co/h-BN heterostructures: First principles calculations","authors":"Dian Putri Hastuti ,&nbsp;Yukie Kitaoka ,&nbsp;Hiroshi Imamura","doi":"10.1016/j.jmmm.2025.173282","DOIUrl":"10.1016/j.jmmm.2025.173282","url":null,"abstract":"<div><div>Magnetic anisotropy (MA) is an important characteristic of magnetic films for the application of spintronics devices such as magnetoresistive random access memories (MRAMs) and magnetic field sensors. Perpendicular MA is more suitable for MRAM, while in-plane MA is better for magnetic field sensor applications. Hexagonal boron nitride (h-BN) has recently attracted much attention as an efficient tunnel barrier for magnetic tunnel junctions with hexagonal symmetry. In this study, the magnetic anisotropy of a Co thin film deposited on h-BN is theoretically investigated using first-principles calculations. It is observed that a substantial perpendicular magnetocrystalline anisotropy (MCA) of the order of 1 mJ/m² is achieved for the film comprising 1 <span><math><mo>∼</mo></math></span> 5 Co atomic layers. The buckled structure of the h-BN layer at the interface is found to enhance the perpendicular MCA. The magnetic dipole energy is also calculated and is found to cause the in-plane MA for the films comprising 2 <span><math><mo>∼</mo></math></span> 5 Co atomic layers. The film comprising a monoatomic Co layer is found to be perpendicularly magnetised with an anisotropy constant of 1.68 mJ/m² and a voltage-controlled MA coefficient of -175 fJ/Vm, which are of the same order as those for the Fe/MgO film. In the case of in-plane magnetised films comprising 2 <span><math><mo>∼</mo></math></span> 5 Co atomic layers, the MA energy is found to be independent of the in-plane angle, which is a preferable characteristic for sensor applications. The results provide fundamental insights into the MA of Co/h-BN heterostructures and a foundation for developing voltage-controlled MRAM and magnetic field sensors based on this material.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173282"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534923","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 of magnetic, thermodynamic, and transport properties in orthorhombic GdNiAl3","authors":"S. Nallamuthu ,&nbsp;K. Arun ,&nbsp;A.R. Vimaljith ,&nbsp;Sergej Ilkovic ,&nbsp;Ivan Curlik ,&nbsp;Marian Reiffers ,&nbsp;R. Nagalakshmi","doi":"10.1016/j.jmmm.2025.173319","DOIUrl":"10.1016/j.jmmm.2025.173319","url":null,"abstract":"<div><div>The compound GdNiAl₃ crystallizes in an orthorhombic structure with the space group Pnma. Magnetization and heat capacity measurements reveal the presence of multiple magnetic transitions below the ordering temperature T_ord = 72.5 K, suggesting the existence of competing magnetic interactions within the system. This behavior is likely associated with the structural complexity of GdNiAl₃, which features randomly oriented Ni-centered tricapped trigonal prisms, further coordinated by additional aluminum atoms. Additionally, a ferromagnetic transition observed at 165.5 K is attributed to the presence of a GdAl₂ impurity phase.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173319"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471056","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":"Broadband tunable YIG film resonator with high loaded-Q and spurious mode suppression","authors":"Xinan Fan ,&nbsp;Qinghui Yang ,&nbsp;Yuanjing Zhang ,&nbsp;Feng Wang ,&nbsp;Shanshan Du ,&nbsp;Lingtong Liu ,&nbsp;Ming Wang ,&nbsp;Huaiwu Zhang","doi":"10.1016/j.jmmm.2025.173289","DOIUrl":"10.1016/j.jmmm.2025.173289","url":null,"abstract":"<div><div>In this work, a broadband tunable high load factor (<span><math><msub><mrow><mi>Q</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span>) resonator based on yttrium iron garnet (YIG) films is proposed. Single-crystal YIG wafers were prepared on [111] crystal-oriented GGG substrates by liquid phase epitaxy (LPE) technique, and the samples were thinned to 100 um by chemical–mechanical polishing process to obtain excellent crystal quality with magnetic resonance linewidths as low as 1.8 <span><math><mrow><mi>O</mi><mi>e</mi></mrow></math></span>. The resonator structure consists of an alumina ceramic substrate, a coplanar waveguide (CPW), and an open resonance ring (SRR). The CPW is used to excite magnetic resonance in the YIG film, and placing the YIG film on the backside of the CPW effectively enhances the uniformity of the microwave field, while the SRR structure further improves the uniformity of the magnetic field distribution. Experimental results demonstrate that the resonator exhibits excellent performance in the 5–25 GHz tuning range, with <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>11</mn></mrow></msub></math></span> parameters better than −5.2 dB, <span><math><msub><mrow><mi>Q</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> values above 700 and the maximum figure of merit (FOM) is 17.21 at 14 GHz. In addition, the resonator successfully suppresses the higher-order spurious modes and maintains good spectral characteristics, which is promising for the application in the field of ultra-wideband tunable devices and microwave systems.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173289"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523377","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":"Enhancing the Tb utilization efficiency and coercivity in high Ce content Nd-Fe-B magnets by Pr-Tb-Zn grain boundary diffusion","authors":"Zhibin Li ,&nbsp;Wenbing Fan ,&nbsp;Rongshun Lai,&nbsp;Haibo Xu,&nbsp;Xiaoxuan Zheng,&nbsp;Xin Wang,&nbsp;Qianji Wang,&nbsp;Bo Jiang,&nbsp;Xianglong Zhou,&nbsp;Qiang Ma","doi":"10.1016/j.jmmm.2025.173316","DOIUrl":"10.1016/j.jmmm.2025.173316","url":null,"abstract":"<div><div>Grain boundary diffusion is an effective method for improving the coercivity of Nd-Fe-B sintered magnets. However, the coercivity is not significantly enhanced after grain boundary diffusion in magnets with high Ce content due to the presence of the REFe₂ phase. In this study, we have designed a novel low-melting-point ternary diffusion source of Pr₅₃Tb₄₂Zn₅ that can effectively improve the diffusion efficiency and utilization of Tb, thereby significantly enhancing the coercivity of the magnets. After diffusion of Tb and Pr₅₃Tb₄₂Zn₅ in sintered magnets with 25.8 wt% Ce substituted, the coercivity of the magnets was enhanced from 1019.7 kA/m to 1412.9 and 1500.5 kA/m, respectively. Observations of the microstructure and element distribution showed that after diffusion of Tb and Pr₅₃Tb₄₂Zn₅, Tb penetrated the surface of the RE₂Fe₁₄B main phase grains and formed a Tb-rich shell, which significantly increased its anisotropy field. Compared to the Tb diffused magnets, the Pr₅₃Tb₄₂Zn₅ diffused magnets exhibited a more uniform distribution of the Tb-rich shell and a deeper diffusion depth. Additionally, transmission electron microscopy analysis indicated that in the Tb diffused magnets, some Tb elements were consumed by the REFe₂ phase, whereas in the Pr₅₃Tb₄₂Zn₅ diffused magnets, there was almost no Tb in the REFe₂ phase, which improved the utilization of Tb and resulted in a higher increment in coercivity.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173316"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144479947","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":"Effect of Mn substitution on first order antiferromagnetic–ferromagnetic phase transition and magnetocaloric effect in FeRh","authors":"Rajeev Joshi ,&nbsp;Pramod R. Nadig ,&nbsp;Satish Yadav ,&nbsp;Suman Karmakar ,&nbsp;R. Rawat","doi":"10.1016/j.jmmm.2025.173217","DOIUrl":"10.1016/j.jmmm.2025.173217","url":null,"abstract":"<div><div>Influence of Mn substitution on the first order antiferromagnetic (AF) to ferromagnetic (FM) transition and magnetocaloric effect (MCE) in FeRh has been investigated. It shows that 1.2% Mn substitution for Fe in Fe₄₉Rh₅₁ decreases transition temperature to around 285 K. Though a majority of sample volume transforms with a hysteresis of <span><math><mo>≈</mo></math></span>10 K, a narrow hysteresis remains over a wide temperature (<span><math><mo>&gt;</mo></math></span> <span><math><mrow><mn>150</mn></mrow></math></span> K) and field (<span><math><mo>&gt;</mo></math></span> <span><math><mrow><mn>90</mn></mrow></math></span> kOe) range. The values of isothermal change in entropy (<span><math><mi>Δ</mi></math></span>S<span><math><msub><mrow></mrow><mrow><mi>t</mi><mi>h</mi></mrow></msub></math></span>) and adiabatic change in temperature (<span><math><mi>Δ</mi></math></span>T<span><math><msub><mrow></mrow><mrow><mi>a</mi><mi>d</mi></mrow></msub></math></span>) were found to be 14 J/kg-K and -7 K, respectively for 50 kOe magnetic field change which are comparable to the maximum values observed in FeRh system.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173217"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490464","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":"Magnetoelectric effect behavior in layered perovskite-type of (1-x) BaTiO3–X MgFe2O4 composites","authors":"Padmapriya Durairaj ,&nbsp;M.T. Rahul ,&nbsp;Kalarikkal Nandhakumar ,&nbsp;Muneeswaran Muniyandi ,&nbsp;N.V. Giridharan","doi":"10.1016/j.jmmm.2025.173317","DOIUrl":"10.1016/j.jmmm.2025.173317","url":null,"abstract":"<div><div>The room temperature multiferroic behavior of (1-x)BaTiO₃- xMgFe₂O₄ (x = 0.05, 0.15, 0.25, 0.35 and 0.45) 0–3 particulate and 2–2 laminated composites has been investigated. Powder X-Ray diffraction data confirms the formation of both perovskite tetragonal BTO and spinel cubic MFO phases coexist with the absence of impurity phases in the detectable limit. The SEM image of the composite samples provides an evidence for presence of two different phases (ferroelectric BTO and ferrite MFO) with different grain size and morphology. An enhancement of magnetization with the increase of ferrite molar fraction in the particulate composites reveals the unbalanced anti parallel spins between Fe³⁺ and Mg²⁺ ions attributes the magnetic property of the composites. Leakage, dielectric and ferroelectric properties of the particulate composites clearly shows leaky behavior of composites with the increase of MgFe₂O₄ concentration. Eventually, 0.65BaTiO₃–0.35MgFe₂O₄ laminated composite with sandwich structure showed better ME coupling than 2–2 laminated bilayer and 0–3 particulate ceramic composites.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173317"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501211","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}