Journal of Magnetism and Magnetic Materials最新文献

{"title":"Impact of strain and stoichiometric variations on the magnetic and electronic properties of RVO₃ (R = La, Pr, Y) thin films","authors":"Shivank Kalia ,&nbsp;Varun Ranade ,&nbsp;Keun Hwa Chae ,&nbsp;Rajesh Kumar ,&nbsp;Ravi Kumar","doi":"10.1016/j.jmmm.2025.173552","DOIUrl":"10.1016/j.jmmm.2025.173552","url":null,"abstract":"<div><div>This study demonstrates that controlled engineering of strain and stoichiometry can dramatically alter the magnetic properties of RVO₃ (R = Pr, La, Y) thin films. X-ray diffraction measurements reveal substrate-induced distortions of the VO₆ octahedra, indicative of strain-driven changes in the local crystal environment. V <em>L</em>_<em>3,2</em>-edge X-ray absorption spectroscopy (XAS) indicates a spatial variation in vanadium oxidation states, with V⁴⁺ predominantly confined to the film surface and a bulk composition dominated by V³⁺ in PrVO₃, while LaVO₃ and YVO₃ exhibit mixed V³⁺/V⁴⁺ valence states. Complementary O <em>K</em>-edge XAS measurements show stoichiometry-dependent modifications in the crystal field environment and V<img>O bond lengths, highlighting further distortions in the octahedral geometry. Magnetization measurements reveal a reduction of the antiferromagnetic ordering temperature by ∼25 K in PrVO₃ relative to the bulk, attributed to altered V–O–V bond angles and V<img>V bond distances, thereby impacting superexchange interactions. Additionally, PrVO₃ exhibits a pinched hysteresis loop, which reflects a superposition of a robust hard component, arising from microstructural variants that act as strong pinning centers, and a soft contribution with dual origins: an intrinsic low-temperature signal from weak canting and/or Pr<img>V interactions below ∼20 K, and an extrinsic enhancement associated with a V⁴⁺-rich paramagnetic dead layer at the film surface. In contrast to their antiferromagnetic bulk counterparts, LaVO₃ and YVO₃ thin films exhibit an emergent weak room-temperature ferromagnetic phase, as evidenced by bifurcations in zero-field-cooled and field-cooled magnetization curves and well-defined hysteresis loops persisting up to room temperature. This behaviour is attributed to stoichiometry-induced mixed valence states, wherein the coexistence of V³⁺ and V⁴⁺ ions may facilitate the formation of localized ferromagnetic regions embedded within an antiferromagnetic matrix. These findings demonstrate that controlled strain and stoichiometry engineering can effectively tune the magnetic properties of RVO₃ thin films, offering pathways for designing novel functional materials.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"633 ","pages":"Article 173552"},"PeriodicalIF":3.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183432","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":"Coercivity enhancement and microstructure evolution in Nd-Fe-B sintered magnets by grain boundary diffusing Pr-Co-Al-Ga alloys","authors":"Shuai Cao ,&nbsp;Peiyi Cheng ,&nbsp;Chenglong Li ,&nbsp;Chen Zhang ,&nbsp;Guangfei Ding ,&nbsp;Yuheng Xie ,&nbsp;Xiaodong Fan ,&nbsp;Shuai Guo ,&nbsp;Bo Zheng ,&nbsp;Renjie Chen ,&nbsp;Aru Yan","doi":"10.1016/j.jmmm.2025.173549","DOIUrl":"10.1016/j.jmmm.2025.173549","url":null,"abstract":"<div><div>Non-heavy-rare-earth Pr₆₇Co₁₂Al₉Ga₁₂ (at.%) alloys were designed as the diffusion sources to conduct grain boundary diffusion (GBD) on commercial Nd-Fe-B sintered magnets. The coating amounts of diffusion source alloys were varied from 1.0 wt% to 11.0 wt%. Magnetic property analyses revealed that the coercivities of the diffused magnets gradually improved with the increasing coating amounts of Pr-Co-Al-Ga alloys, accompanied by the corresponding decreases in both the remanences and maximum magnetic energy products. At 11.0 wt% coating, the coercivity significantly increased from 14.35 kOe (original magnet) to 25.19 kOe. Microstructural analysis demonstrated that the significant coercivity enhancement after diffusion primarily resulted from the formation of continuous and clear grain boundaries in the surface layers. Meanwhile, the multi-element content analysis showed that the residual amounts of diffusion-source alloys after GBD increased with the pre-diffusion coating amounts, and both Al and Ga elements in the alloys were more easily diffused into the interiors of the magnets compared to Pr. Besides, diffusion behaviors of Pr-Co-Al-Ga alloys in the whole GBD process both on the surface of the magnet and in the shallow surface-layer inside the magnet were studied systematically by the in-situ confocal laser scanning and element distribution analyses for GBD intermediate states respectively, demonstrating that the Pr-Co-Al-Ga alloys diffused into magnet interiors at temperatures far below that of conventional GBD treatment (∼900 °C) and the typical continuous grain boundaries formed predominantly during 500 °C annealing stage. Complementary micromagnetic simulations further elucidated the effects of grain boundary modification on demagnetization processes. This work provided insights and experimental foundations for advancing non-heavy-rare-earth GBD technology.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"633 ","pages":"Article 173549"},"PeriodicalIF":3.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183433","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":"The fabrication, magnetic and transport properties of Cr2CoAl films with fully-compensated ferrimagnetic half-metallicity, and the enhancement of Néel temperature by Cr buffer layer","authors":"Chunhai Liu ,&nbsp;Xuefang Dai ,&nbsp;Liying Wang ,&nbsp;Lei Jin ,&nbsp;Cong Liu ,&nbsp;Xiaoming Zhang ,&nbsp;Ying Liu ,&nbsp;Guodong Liu","doi":"10.1016/j.jmmm.2025.173543","DOIUrl":"10.1016/j.jmmm.2025.173543","url":null,"abstract":"<div><div>Fully-compensated ferrimagnetic half-metals, characterized by ordered spin configurations, vanishing net magnetization, suppressed stray fields, and terahertz-range spin dynamic response, hold significant promise in spintronics devices. In this work, Cr₂CoAl thin films with high atomic order were fabricated via magnetron sputtering. Comprehensive investigations of their magnetic and electrical transport properties, combined with theoretical calculations, confirm the material's fully-compensated ferrimagnetic half-metallicity. Introducing a Cr buffer layer was found to improve the phase formation capability and enhance the atomic arrangement orderliness in Cr₂CoAl. Crucially, the Néel temperature of Cr₂CoAl was elevated to 310 K via the Cr layer. The Cr/Cr₂CoAl interface exhibited negligible lattice mismatch while preserving the electron spin polarization of the Cr₂CoAl layer. These results demonstrate the realization of a Cr/Cr₂CoAl magnetic heterojunction with zero net magnetic moment, offering significant potential for advanced spintronic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"633 ","pages":"Article 173543"},"PeriodicalIF":3.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183430","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":"A simple feature enriched CGCNN for predicting magnetization in transition metal compounds","authors":"Sandeep Singh,&nbsp;Parth Joshi,&nbsp;Abhishek Sharma,&nbsp;Arti Kashyap","doi":"10.1016/j.jmmm.2025.173541","DOIUrl":"10.1016/j.jmmm.2025.173541","url":null,"abstract":"<div><div>Accurate prediction of magnetic properties is essential for accelerating the discovery and modeling of magnetic materials. While machine learning methods such as Orbital Field Matrix capture ferromagnetic (FM) systems fairly well, there is a lack of approaches tailored for ferrimagnetic (FiM) compounds, whose complex yet technologically vital behavior remains largely unexplored. To address this, we extend the Crystal Graph Convolutional Neural Network (CGCNN) by integrating atomic spin magnetic moments as node attributes and structural parameters as edge attributes. This enhancement enables the network to outperform existing methods for FM materials and effectively model magnetism in FiM compounds. We utilize the Materials Project database to curate datasets comprising 3d transition-metal (TM) compounds for the training and evaluation of the model. The trained model generalizes effectively to unseen complex systems and demonstrates strong transferability across experimental and computational datasets of TM and rare-earth compounds. In materials families like Heusler alloys and MXenes, accuracy improves with minimal representative data during training. This enables accurate predictions for novel and unique magnetic compounds, even with limited datasets.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"633 ","pages":"Article 173541"},"PeriodicalIF":3.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183434","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 chemical etching on stress induced magnetic anisotropy of amorphous microwires","authors":"Somnath Das ,&nbsp;Dev Kumar Mahato ,&nbsp;Ashis Kumar Panda ,&nbsp;Premkumar Murugaiyan ,&nbsp;Rajat Kumar Roy","doi":"10.1016/j.jmmm.2025.173547","DOIUrl":"10.1016/j.jmmm.2025.173547","url":null,"abstract":"<div><div>The investigation explores the influence of chemical etching on the Giant Magneto-Impedance (GMI) properties of microwires, considering variations in their diameters and driving frequencies. The thinner microwire (D₅₀) exhibits the most significant magneto-impedance change compared to the as-quenched microwire (D₇₀). The intriguing physics behind the dual-peak transition phenomenon has been investigated, including the transitions in peak intensities and the transformation from dual peak to a single peak, in relation to the microwire diameter. As the microwire diameter decreases during chemical etching, both the slope (magnetic field sensitivity) and the anisotropy field (&lt;H_k&gt;) exhibit an increasing trend at higher driving frequencies. Thus, the magnetic properties of as-quenched amorphous microwires can be effectively controlled and tuned through chemical etching.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"633 ","pages":"Article 173547"},"PeriodicalIF":3.0,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183431","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":"Rolling and propulsion of self-assembled magnetic clusters in confined environments","authors":"M.A. Digón ,&nbsp;E.A. Gonzalez ,&nbsp;A. Frisco ,&nbsp;M. Morales ,&nbsp;C.E. Chiliotte ,&nbsp;J.A. Alliende González ,&nbsp;C. Ferrari ,&nbsp;G. Berlin ,&nbsp;C. Kettmayer ,&nbsp;L.C. Estrada ,&nbsp;V. Bekeris ,&nbsp;G.A. Jorge","doi":"10.1016/j.jmmm.2025.173522","DOIUrl":"10.1016/j.jmmm.2025.173522","url":null,"abstract":"<div><div>We investigate the dynamics of magnetic particles subjected to rotating magnetic fields, focusing on the influence of confinement geometry on their collective motion. Two experimental configurations were studied: two-dimensional (2D) confinement, where particles move freely on a flat solid–liquid interface, and one-dimensional (1D) confinement within narrow microchannels. In both cases, external magnetic actuation leads to the formation of self-assembled elongated clusters that exhibit directed motion. We perform detailed particle tracking and propose a scaling analysis of the translational velocity normalized by the angular frequency (<span><math><mrow><mi>v</mi><mo>/</mo><mi>ω</mi></mrow></math></span>) as a function of cluster length. Our results demonstrate that, under 2D confinement, clusters display rolling-like behavior consistent with theoretical predictions for non-slipping elongated bodies. In contrast, the introduction of geometric constraints in 1D confinement significantly reduces locomotion efficiency, as evidenced by lower <span><math><mrow><mi>v</mi><mo>/</mo><mi>ω</mi></mrow></math></span> values. These findings highlight the critical role of morphology and environmental constraints in the magnetic actuation and transport of microstructured aggregates. The proposed framework provides information for optimizing design principles in magnetically driven microrobotics operating in restricted environments.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173522"},"PeriodicalIF":3.0,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156468","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 topological properties of quaternary Heusler alloy CoMnVAl and CoMnCrSi: A first-principles study","authors":"Madhumita Halder,&nbsp;Athira Venugopalan,&nbsp;Raghu Chatanathodi","doi":"10.1016/j.jmmm.2025.173539","DOIUrl":"10.1016/j.jmmm.2025.173539","url":null,"abstract":"<div><div>The electronic, magnetic, and topological properties of quaternary Heusler alloys CoMnVAl and CoMnCrSi have been studied. A combination of density functional theory and tight-binding approximation has been used to investigate the electronic structure and the topological properties of these alloys. Our study shows that CoMnVAl is a non-magnetic semimetal, while CoMnCrSi is a magnetic semimetal. Berry curvature is observed in both alloys, which results in an intrinsic anomalous Hall conductivity of 17 S/cm and 50 S/cm for CoMnVAl and CoMnCrSi, respectively, at the Fermi energy. The flat band-like surface states and nodal ring-like structures are observed in the Fermi surface, which indicates that both alloys are topological nodal line semimetal.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"633 ","pages":"Article 173539"},"PeriodicalIF":3.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183429","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 half-metallicity of equiatomic quaternary Heusler compound OsZrTiSi via atomic doping","authors":"Xiao-Wei Sun,&nbsp;Hao Wu,&nbsp;Shuang-Gang Xu,&nbsp;Ting Song,&nbsp;Zi-Jiang Liu","doi":"10.1016/j.jmmm.2025.173517","DOIUrl":"10.1016/j.jmmm.2025.173517","url":null,"abstract":"<div><div>The quaternary Heusler alloy OsZrTiSi has been proven to be a half-metallic ferromagnet. However, the Curie temperature of OsZrTiSi does not exceed room temperature, which limits its applications. The Curie temperature is increased by doping vanadium atoms, and compounds with the desired magnetic moment are obtained in this work. Vanadium (V) and Titanium (Ti) belong to the same period. By substituting V for Ti atoms, compounds with tailored magnetic moments can be obtained, thereby enabling magnetic property tuning. In addition, the Curie temperatures of OsZrTi_nV_1-nSi (<em>n</em> = 0.25, 0.5, 0.75, 1.0) obtained after doping are 430.3 K, 475.5 K, 520.8 K and 566 K respectively, all of which are higher than room temperature. This study provides a new approach for the design of multifunctional novel Heusler alloys.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173517"},"PeriodicalIF":3.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156467","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":"The magnetic scalar potential and demagnetization vector for a cylinder tile","authors":"Rasmus Bjørk","doi":"10.1016/j.jmmm.2025.173519","DOIUrl":"10.1016/j.jmmm.2025.173519","url":null,"abstract":"<div><div>A closed-form solution for the magnetic scalar potential generated by a uniformly magnetized cylindrical slice and a full cylinder is determined by solving Poisson’s equation analytically. The solution is given in terms of elliptic integrals of the first, second and third kind. We show that the magnetic scalar potential can be written as the dot product of a demagnetization vector, containing all the geometric information of the generating cylinder, and the magnetization. We validate the derived analytical expressions for the magnetic scalar potential by comparing with a finite element simulation and show that these agree perfectly for both the cylindrical slice and the full cylinder.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173519"},"PeriodicalIF":3.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156471","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":"General structure factor and dynamic effects of the Dzyaloshinskii–Moriya interaction in S = 1/2 clusters","authors":"Evan M. Wilson,&nbsp;Joseph A. Prescott,&nbsp;Jason T. Haraldsen","doi":"10.1016/j.jmmm.2025.173501","DOIUrl":"10.1016/j.jmmm.2025.173501","url":null,"abstract":"<div><div>Understanding the effects of the Dzyaloshinskii–Moriya interaction (DMI) has become increasingly important in the context of nanoscale magnetism and spintronics. In this study, we derive a general structure factor equation for an S = 1/2 dimer and show that the anisotropic ratio <span><math><mrow><msub><mrow><mi>D</mi></mrow><mrow><mi>z</mi></mrow></msub><mo>/</mo><mrow><mo>|</mo><mi>J</mi><mo>|</mo></mrow></mrow></math></span> and complex phase <span><math><mi>ϕ</mi></math></span> of the DMI control the gap energy and intensity of the <span><math><mrow><mrow><mo>|</mo><mn>0</mn><mo>,</mo><mn>0</mn><mo>〉</mo></mrow><mo>→</mo><mrow><mo>|</mo><mn>1</mn><mo>,</mo><mn>0</mn><mo>〉</mo></mrow></mrow></math></span> transition. Using exact diagonalization of the Heisenberg spin–spin Hamiltonian that incorporates both isotropic and anisotropic interactions, as well as the effects of an external magnetic field and an electric field. Our results show that the DM interaction splits energy eigenstates, induces level repulsion, and significantly modifies the spin dimer structure factor. These effects reveal a direct correspondence between thermodynamic anomalies in the heat capacity and spin-resolved selection rules.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"632 ","pages":"Article 173501"},"PeriodicalIF":3.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156459","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}