Journal of Magnetism and Magnetic Materials最新文献

{"title":"Maghemite and hematite nanowires synthesized by nanocasting: precursor effects on structural and magnetic properties","authors":"Natalia I. Cuello ,&nbsp;Emiliano G. Fornasin ,&nbsp;Marcos I. Oliva ,&nbsp;Gerardo F. Goya ,&nbsp;Gustavo Marchetti ,&nbsp;Griselda A. Eimer ,&nbsp;Verónica R. Elías","doi":"10.1016/j.jmmm.2025.173288","DOIUrl":"10.1016/j.jmmm.2025.173288","url":null,"abstract":"<div><div>Mesoporous iron oxides with tailored structural and magnetic properties were synthesized using the SBA-15 silica template and two different iron precursors: Fe(NO₃)₃·9H₂O and Fe(C₅H₇O₂)₃, denoted as FeM-1 and FeM-2, respectively. The synthesis involved a two-step impregnation-calcination process followed by silica removal. Comprehensive characterization was performed using techniques such as nitrogen adsorption–desorption isotherms, TEM, SEM-EDX, XRD, XPS, and Mössbauer spectroscopy, as well as magnetic measurements.</div><div>The results revealed significant differences in structural and magnetic properties between the two samples. FeM-1 exhibited higher structural order, greater homogeneity, and a single-phase α-Fe₂O₃ composition, whereas FeM-2 showed a bimodal pore size distribution and a dual-phase composition of α-Fe₂O₃ and ɣ-Fe₂O₃. Magnetic characterization indicated enhanced magnetization in FeM-2 due to the ferrimagnetic nature of ɣ-Fe₂O₃, while FeM-1 displayed lower magnetization consistent with the weak ferromagnetic behavior of α-Fe₂O₃. The combination of structural and magnetic analyses demonstrated the critical role of precursor selection in tuning the material properties for potential applications in catalysis and magnetic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173288"},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313490","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":"Large reversible magnetocaloric effect in GdPO4 nano-spherical particles at ultralow temperatures","authors":"Meryam Lassri ,&nbsp;Said El Ouahbi ,&nbsp;Imane Abdelrhafore ,&nbsp;Lhaj El Hachemi Omari ,&nbsp;Abdelhadi El Hachmi ,&nbsp;Hassan Hamouda ,&nbsp;Benaissa Harradi ,&nbsp;Yousra Ounza ,&nbsp;Gianluca Viscusi ,&nbsp;Claire Minaud ,&nbsp;Charafeddine Jama ,&nbsp;Hassan Lassri","doi":"10.1016/j.jmmm.2025.173291","DOIUrl":"10.1016/j.jmmm.2025.173291","url":null,"abstract":"<div><div>This study reports the synthesis of gadolinium phosphate (GdPO₄) with a monoclinic crystal structure (<em>P2₁</em>/<em>n</em>) using a high-temperature solid-state reaction method. Rietveld refinement of the X-ray diffraction (XRD) data revealed lattice constants of <em>a</em> = 0.66497(5) nm, <em>b</em> = 0.68457(5) nm, and <em>c</em> = 0.63327(4) nm. The magnetic and magnetocaloric properties of GdPO₄ were investigated in detail. The ferromagnetic (FM) to paramagnetic (PM) phase transition temperature was determined to be around 1.8 K. The transition was strongly supported by Arrott plots and a universal phenomenological curve describing the magnetocaloric effect (MCE). GdPO₄ exhibits significant magnetic entropy changes (−ΔS_M). The maximum values of <span><math><mrow><mo>-</mo><mi>Δ</mi><msubsup><mtext>S</mtext><mrow><mtext>M</mtext></mrow><mtext>max</mtext></msubsup></mrow></math></span> are 20.43 J/(kg·K) and 44.79 J/(kg·K) for a magnetic field change (μ₀ΔH) of 2 T and 9 T, respectively. Our analysis indicates that the GdPO₄ nano-spherical particles exhibit short-range magnetic ordering, characterized by the coexistence of ferromagnetic (FM) and antiferromagnetic (AFM) interactions.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173291"},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290651","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":"Computational study of magnetic behaviour in Ni-adsorbed Nb2C-OF MXene using density functional theory","authors":"Zarah Khan ,&nbsp;Saleem Ayaz Khan ,&nbsp;Ayesha Zaheer ,&nbsp;Syed Rizwan","doi":"10.1016/j.jmmm.2025.173261","DOIUrl":"10.1016/j.jmmm.2025.173261","url":null,"abstract":"<div><div>Magnetic 2D materials have achieved significantly consideration owing to their encouraging applications. A variation of these 2D materials by occurrence of defects, by the transition-metal doping or adsorption or by the surface functionalization can initiate both the spin-polarization and magnetic properties in these materials. Density functional theory (DFT) is used to determine the electric, magnetic properties along with the electronic structures and stability of synthesized two-dimensional materials. This work describes the magnetic properties of Ni-ad-Nb₂C-OF MXene. The study focuses on the computational approach based first principal calculation providing insight onto the magnetic properties of adsorbed compound and comparing it with pristine Nb₂C-OF MXene. The pristine Nb₂C-OF and Ni-ad-Nb₂C-OF structures are simulated and optimized using Wien2k software. Using exchange-correlational functionals; spin-GGA and spin-GGA + U (for Nickel U = 6 eV), Ni-ad-Nb₂C-OF electronic band structure is found to be metallic having magnetic moment calculated + 1.01516 <span><math><msub><mi>μ</mi><mi>β</mi></msub></math></span> showing its non-superconducting and ferromagnetic properties. Owing to this magnetic properties, this 2D compound holds potential for emerging applications in spintronics and nanoscale magnetic data storage technologies.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173261"},"PeriodicalIF":2.5,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270430","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":"Understanding dynamic frequency-matching resonance driven magnetic switching","authors":"Jian-Gang (Jimmy) Zhu","doi":"10.1016/j.jmmm.2025.173281","DOIUrl":"10.1016/j.jmmm.2025.173281","url":null,"abstract":"<div><div>Aiding magnetization reversal of a single domain particle usingan ac magnetic field at resonance condition can lower the switching field threshold. This is the underlying mechanism for microwave assisted magnetic recording. However, the resonance frequency changes during the reversal of magnetic particles with uniaxial anisotropy. For an ac field with constant frequency, resonance conditions cannot be maintained during a reversal process, thereby limiting the effectiveness of the ac field assistance. In this paper, we provide an in-depth analysis on the effect of time varying frequency ac field for the magnetization reversal. It is found that matching the ac field frequency with the particle’s resonance frequency would yield a 90° phase angle between the field and the magnetization, the optimal condition for maximizing driving torque by the ac field. Matching this optimal condition, even approximately, magnetization reversal can be solely accomplished by the ac field alone.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173281"},"PeriodicalIF":2.5,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263272","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 and electronic properties of bulk and (111), (001), and (110) surfaces of the Heusler Zr2RhIn alloy","authors":"Hassan I. Asker ,&nbsp;Jabbar M. Khalaf Al-zyadi ,&nbsp;Munira W. Mahan","doi":"10.1016/j.jmmm.2025.173285","DOIUrl":"10.1016/j.jmmm.2025.173285","url":null,"abstract":"<div><div>The electronic and magnetism properties of the bulk as well as (111), (110), and (001) surfaces of Heusler alloy Zr₂RhIn have been studied by using first-principles calculations with (GGA-PBE) method. According to calculations, the compound Zr₂RhIn exhibits full spin polarization and half-metallic ferromagnetic behavior at an equilibrium lattice constant of 6.8 ± 0.01 Å. The energy gap and spin flip gap in the minority channel are 0.47 and 0.11 eV, respectively. The total magnetic moment is 2 ± 0.05 µ_B which agrees with the Slater-Pauling rule. The electronic, magnetism properties and atomic relaxation were examined for the (1<!--> <!-->1<!--> <!-->1), (0<!--> <!-->0<!--> <!-->1), and (1<!--> <!-->1<!--> <!-->0) surfaces of the Zr₂RhIn alloy. The results confirm that the half-metallic property was preserved at Zr1-, Zr2-, and In-terminations (1<!--> <!-->1<!--> <!-->1) surfaces, but disappeared at Rh-terminated (1<!--> <!-->1<!--> <!-->1) surface due to the surface states, likewise disappeared at (0<!--> <!-->0<!--> <!-->1) and (1<!--> <!-->1<!--> <!-->0) surfaces. These findings highlight the sensitivity of half-metallicity to surface orientation and termination, making Zr₂RhIn a promising candidate for spintronic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173285"},"PeriodicalIF":2.5,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263304","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":"Design of audio to image cross-modal learning and generation based on single-layer CoPt spin-orbit torque devices","authors":"Likun Qian ,&nbsp;Liu Yang ,&nbsp;Chao Zuo ,&nbsp;Ying Tao ,&nbsp;Wendi Li ,&nbsp;Fang Jin ,&nbsp;Huihui Li ,&nbsp;Kaifeng Dong","doi":"10.1016/j.jmmm.2025.173279","DOIUrl":"10.1016/j.jmmm.2025.173279","url":null,"abstract":"<div><div>Despite remarkable achievements in neural network applications using spin–orbit torque (SOT) devices, current research predominantly focuses on unimodal classification tasks, while cross-modal learning tasks often suffer from suboptimal generation quality. To address this limitation, we employ generative adversarial networks (GANs) based on CoPt-SOT to achieve cross-modal learning and generation from speech to handwritten digit images. Initially, we explore the field-free switching characteristics of single-layer CoPt devices, developing spin-based implementations of Scaled Rectified Linear Unit (SReLu), Sigmoid, and Tanh neuronal functions. Simultaneously, we leverage the nonvolatile multistate characteristics of CoPt devices to realize excitatory-inhibitory synaptic plasticity. Subsequently, for the first time, we construct half-spin and full-spin GAN networks using these spin-based neurons and synapses, enabling cross-modal learning and generation between speech and image domains. Finally, we evaluate the performance of these networks through handwritten digit recognition tasks, achieving impressive recognition accuracies of 93.78 % and 88.61 % for half-spin and full-spin implementations, respectively. Notably, this work overcomes the existing bottleneck in SOT device applications, which have been largely confined to unimodal classification tasks, and demonstrates significant potential for expanding the scope of SOT-based technologies.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173279"},"PeriodicalIF":2.5,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240163","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":"Design and performance analysis of magnetic helical robot used for vascular interventions","authors":"Pan Li ,&nbsp;Chongcong Ye ,&nbsp;Zhichao Wang ,&nbsp;Jiarui Zhang ,&nbsp;Qi Xue ,&nbsp;Delei Fang ,&nbsp;Junxia Zhang ,&nbsp;Cunman Liang","doi":"10.1016/j.jmmm.2025.173267","DOIUrl":"10.1016/j.jmmm.2025.173267","url":null,"abstract":"<div><div>During minimally invasive vascular interventions, the maneuverability of guidewires is usually limited by narrow blood vessels. In this study, we designed a magnetic helical robot capable of overcoming spatial constraints within narrow blood vessels and precisely navigating guidewires to target regions. The structure of the magnetic helical robot consists of a front-end permanent magnet and helical structure, a flexible body structure, and a trailing guidewire. By considering resistance theory in low Reynolds number environments, we developed a dynamic model for the magnetic helical robot and analyzed the relationship between its motion velocity and helical structure parameters. Based on a guidewire deflection cantilever model, we investigated the relationship between guidewire deflections and flexible body structure parameters. Dynamic experiments were conducted on the magnetic helical robot to verify its active locomotion capability and confirm the optimal helical structure parameters. Additionally, guidewire deflection experiments demonstrated that increasing the length of the flexible body structure resulted in a maximum bending gain of up to 30 %, confirming the enhanced deformability of the carried guidewire and determining the optimal length of the flexible body structure. Furthermore, successful navigation experiments of the magnetic helical robot carrying a guidewire were performed in a three-dimensional vascular model, with a navigation error of 0.80 mm, thereby validating the locomotion and capability of enhancing guidewire deflections of the magnetic helical robot. The designed magnetic helical robot in this study provides experimental evidence for minimally invasive vascular interventions and holds promise for application in vascular intervention procedures.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173267"},"PeriodicalIF":2.5,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270432","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":"Exploring the three-field coupling mechanism of temperature-magnetic stress relief in electrical metal materials","authors":"Gang Huang,&nbsp;Chao Zhou","doi":"10.1016/j.jmmm.2025.173278","DOIUrl":"10.1016/j.jmmm.2025.173278","url":null,"abstract":"<div><div>This paper presents a comparative investigation into the efficacy of temperature-magnetic stress relief (TMSR) applied to silicon steel, along with an analysis of the ensuing microstructural changes post-TMSR treatment. The findings reveal that TMSR exhibits a remarkable “1 + 1 &gt; 2″ reduction effect. Following TMSR treatment, there is a notable increase in dislocations within the material, accompanied by a rise in parallel domains that are uniformly distributed. Furthermore, density functional theory simulations were conducted on Fe crystals subjected to varying temperature fields to examine changes in crystal properties and elucidate the mechanism behind TMSR’s reduction and enhancement effects. The simulation outcomes indicate a consistent upward trend in crystal atomic magnetic moment with increasing temperature, regardless of stress levels, suggesting a pronounced thermos-magnetic coupling strengthening effect. This phenomenon constitutes the primary mechanism driving the attenuation and enhancement effects observed with TMSR. Additionally, systematic calculations were performed to assess the mechanical properties of the crystal under different temperature conditions. The results demonstrate a continuous softening of the crystal with increasing temperature, eventually leading to a phase change upon surpassing a critical temperature threshold.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173278"},"PeriodicalIF":2.5,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240161","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 pressure on the structural, magnetic, dynamical and mechanical properties of α″-Fe16N2","authors":"Tai-min Cheng,&nbsp;Guo-qing chai,&nbsp;Qing-qing Fan,&nbsp;Guo-liang Yu,&nbsp;Xin-xin Zhang","doi":"10.1016/j.jmmm.2025.173277","DOIUrl":"10.1016/j.jmmm.2025.173277","url":null,"abstract":"<div><div>The ground-state properties of the <em>α</em>″-Fe₁₆N₂ compound have been thoroughly studied, while its physical properties under high pressure are unknown. Here, the effect of pressure on the structural, electronic, magnetic, mechanical and dynamical properties of the <em>α</em>″-Fe₁₆N₂ are systematically investigated from the first principles calculations. The theoretical results at 0 GPa are consistent with previous theoretical and experimental values. The critical pressure of ferromagnetic collapse (<em>P</em>_C) is about 61.2 GPa. The magnetic moments of the Fe atoms at 4d and 4e sites are the largest and smallest, respectively. The Fe moments are mainly derived from the spin polarization of the <em>d_z</em>² and <em>d_x</em>²_-<em>_y</em>² electrons. From the phonon spectra, the <em>α</em>″-Fe₁₆N₂ exhibits the dynamic stability below the <em>P</em>_C, and the Fe atoms at the three sites show different vibrational anisotropy under high pressure. According to the <em>B</em>/<em>G</em> and Poisson’s ratios, the Fe₁₆N₂ exhibits excellent metallic ductility below the <em>P</em>_C. The elastic modulus increases with pressure, but softens near the critical pressure. In addition, the elastic anisotropy also mutates near the critical pressure <em>P</em>_C.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173277"},"PeriodicalIF":2.5,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253698","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":"Microfluidic-integrated SSPP sensor for rapid and sensitive label-free honey adulteration","authors":"Shaik Imamvali ,&nbsp;Rishitej Chaparala ,&nbsp;Yuvaraju Chinnam ,&nbsp;Venkateswara Rao Kolli ,&nbsp;Sreenivasulu Tupakula ,&nbsp;Krishna Prakash ,&nbsp;Shonak Bansal ,&nbsp;Mohammad Rashed Iqbal Faruque ,&nbsp;K.S. Al-mugren","doi":"10.1016/j.jmmm.2025.173255","DOIUrl":"10.1016/j.jmmm.2025.173255","url":null,"abstract":"<div><div>A Spoof surface plasmon polariton (SSPP) sensor is developed to identify honey samples by adding different concentrations levels of sugar (glucose and fructose). The SSPP-based sensor is integrated with a microfluidic reservoir to discriminate honey samples. The change in the resonating frequency shift with changed percentages of fructose and glucose levels of honey samples shows the performance of the SSPP sensor. This innovative approach presents a non-destructive, non-intrusive, label-free, rapid, and real-time methodology for analysing honey samples. The sensor exhibits exceptional sensitivity in detecting subtle differences in the dielectric constants of diverse samples. We systematically investigate the impact of distinct geometrical parameters on the sensor’s performance, focusing on optimizing its characteristics. A distinctive pentagon-shaped unit cell (UC) for the SSPP construction is thoroughly explored, revealing its unique performance and sensing capabilities. We construct a multilayer SSPP microwave structure with a pentagon unit cell to create a functional sensing platform for honey samples. The transient solver is used for computational analysis. Our results indicate a remarkable sensitivity of 1522 MHz/epsilon unit, with a correlation coefficient (R²) of 0.9367, for discerning between different dielectric samples ranging from 1 to 5 for normal pentagon unit cells. Additionally, for vertex-based pentagon unit cells, the sensor demonstrates a sensitivity of 1105 MHz/epsilon unit, with an R² of 0.9524, when applied dielectric constants within the range of 1–5. These simulation outcomes highlight the viability of the suggested SSPP-inspired sensor as a promising solution for monitoring applied dielectric quality and characterizing the honey sample’s dielectric constants. This integrated approach showcases the potential to revolutionize quality assessment within the realm of honey production and diverse materials through its advanced sensing capabilities.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"629 ","pages":"Article 173255"},"PeriodicalIF":2.5,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263260","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}