Pub Date : 2026-01-17DOI: 10.1016/j.jmmm.2026.173859
Alberto Ghirri , Mattia Cavani , Claudio Bonizzoni , Marco Affronte
In cavity magnonics, magnon–photon hybridization has been widely investigated for both fundamental studies and applications. Planar superconducting resonators operating at microwave frequencies have demonstrated the possibility to achieve high couplings with magnons by exploiting the confinement of the microwave field in a reduced volume. Here we report a study of the coupling of high- YBCO superconducting waveguides with 104-nm-thick YIG magnetic films. We study the evolution of mode frequencies as a function of temperature and extract the coupling strength of hybrid magnon–photon modes. We show that the experimental results can be reproduced using a simple model in which the temperature dependence of the penetration depth accounts for the evolution of the polaritonic spectrum.
{"title":"Coherent coupling between YBCO superconducting resonators and sub-micrometer-thick YIG films","authors":"Alberto Ghirri , Mattia Cavani , Claudio Bonizzoni , Marco Affronte","doi":"10.1016/j.jmmm.2026.173859","DOIUrl":"10.1016/j.jmmm.2026.173859","url":null,"abstract":"<div><div>In cavity magnonics, magnon–photon hybridization has been widely investigated for both fundamental studies and applications. Planar superconducting resonators operating at microwave frequencies have demonstrated the possibility to achieve high couplings with magnons by exploiting the confinement of the microwave field in a reduced volume. Here we report a study of the coupling of high-<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> YBCO superconducting waveguides with 104-nm-thick YIG magnetic films. We study the evolution of mode frequencies as a function of temperature and extract the coupling strength of hybrid magnon–photon modes. We show that the experimental results can be reproduced using a simple model in which the temperature dependence of the penetration depth accounts for the evolution of the polaritonic spectrum.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173859"},"PeriodicalIF":3.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035308","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}
Pub Date : 2026-01-17DOI: 10.1016/j.jmmm.2026.173857
M. Stella , V. Bertolini , G. Carlotti , A. Faba
For CubeSat nanosatellites, rapid attitude stabilization after orbital deployment is critical for mission success. In this work, we optimize the geometry of hysteresis materials to maximize the dissipation of rotational kinetic energy. We developed an analytical–computational method to compare cylindrical rods and ellipsoids, using experimental data from an additively manufactured Fe–Si 3.7 wt% Si alloy. After optimizing a cylinder’s diameter via Finite Element (FE) simulations, we used its volume as a constraint for the analytical optimization of an ellipsoid. The results, validated by further FE simulations, indicate that ellipsoids yield superior energy losses. Specifically, the optimized ellipsoidal geometry showed a 28% increase in losses. This improvement leads to a significant reduction in attitude stabilization time of approximately 2 days, establishing ellipsoids as the preferable choice for designing compact and efficient passive magnetic attitude control systems.
{"title":"Analytical and computational geometry optimization for nanosatellites magnetic damping systems","authors":"M. Stella , V. Bertolini , G. Carlotti , A. Faba","doi":"10.1016/j.jmmm.2026.173857","DOIUrl":"10.1016/j.jmmm.2026.173857","url":null,"abstract":"<div><div>For CubeSat nanosatellites, rapid attitude stabilization after orbital deployment is critical for mission success. In this work, we optimize the geometry of hysteresis materials to maximize the dissipation of rotational kinetic energy. We developed an analytical–computational method to compare cylindrical rods and ellipsoids, using experimental data from an additively manufactured Fe–Si 3.7 wt% Si alloy. After optimizing a cylinder’s diameter via Finite Element (FE) simulations, we used its volume as a constraint for the analytical optimization of an ellipsoid. The results, validated by further FE simulations, indicate that ellipsoids yield superior energy losses. Specifically, the optimized ellipsoidal geometry showed a 28% increase in losses. This improvement leads to a significant reduction in attitude stabilization time of approximately 2 days, establishing ellipsoids as the preferable choice for designing compact and efficient passive magnetic attitude control systems.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173857"},"PeriodicalIF":3.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035299","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}
Pub Date : 2026-01-17DOI: 10.1016/j.jmmm.2026.173849
M. Anisimov , V. Krasnorussky , A. Bogach , S. Demishev , A. Semeno , D. Salamatin , V. Sidorov , A. Bokov , A. Tsvyashchenko
Antiferromagnet (AFM) YbCoC with the highest for Yb-based compounds Neel temperature 25.8 K is studied by detailed measurements of galvanomagnetic properties [electrical resistivity, transverse magnetoresistance (TMR)] at temperatures 2–300 K and magnetic fields up to 82 kOe. Negative quadratic TMR detected in paramagnetic (PM) state is explained in terms of Yosida’s model, which takes into account the scattering of the conduction electrons on localized magnetic moments (LMMs) of rare-earth (RE) ions. The analysis of both local and bulk magnetic susceptibilities allows proposing the existence of short-range correlations in wide PM vicinity of . The polaronic scenario is suggested. The data obtained allow us to detect the appearance of field-induced TMR hysteresis inside the magnetically ordered state. Magnetic - diagram is also reconstructed and a few additional phase boundaries are assumed. One of them is interpreted as -phase. It stabilizes in the range 71–77 kOe on the boundary between commensurate and incommensurate magnetic structures at 8–9 K.
{"title":"Magnetotransport and rich H-T phase diagram in moderately heavy fermionic antiferromagnet YbCoC2","authors":"M. Anisimov , V. Krasnorussky , A. Bogach , S. Demishev , A. Semeno , D. Salamatin , V. Sidorov , A. Bokov , A. Tsvyashchenko","doi":"10.1016/j.jmmm.2026.173849","DOIUrl":"10.1016/j.jmmm.2026.173849","url":null,"abstract":"<div><div>Antiferromagnet (AFM) YbCoC<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> with the highest for Yb-based compounds Neel temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span> <span><math><mo>≈</mo></math></span> 25.8 K is studied by detailed measurements of galvanomagnetic properties [electrical resistivity, transverse magnetoresistance (TMR)] at temperatures 2–300 K and magnetic fields up to 82 kOe. Negative quadratic TMR detected in paramagnetic (PM) state is explained in terms of Yosida’s model, which takes into account the scattering of the conduction electrons on localized magnetic moments (LMMs) of rare-earth (RE) ions. The analysis of both local and bulk magnetic susceptibilities allows proposing the existence of short-range correlations in wide PM vicinity of <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span>. The polaronic scenario is suggested. The data obtained allow us to detect the appearance of field-induced TMR hysteresis inside the magnetically ordered state. Magnetic <span><math><mi>H</mi></math></span>-<span><math><mi>T</mi></math></span> diagram is also reconstructed and a few additional phase boundaries are assumed. One of them is interpreted as <span><math><mi>A</mi></math></span>-phase. It stabilizes in the range 71–77 kOe on the boundary between commensurate and incommensurate magnetic structures at <span><math><mi>T</mi></math></span> <span><math><mo>≤</mo></math></span>8–9 K.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173849"},"PeriodicalIF":3.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035297","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}
Pub Date : 2026-01-17DOI: 10.1016/j.jmmm.2026.173831
Sijie Min, Kai Liu, Na Li, Zeshuo Jiao, Yiqun Zhang, Bin Zheng
The demand for highly miniaturized antennas in micro-unmanned platforms has motivated the exploration of magnetoelectric (ME) antennas, which achieve sound-electric-magnetic energy conversion through the strong coupling between piezoelectric and magnetostrictive layers. Although ME antennas offer extreme size reduction by leveraging bulk acoustic wave resonance, their performance remains limited due to incomplete understanding of multi-physics coupling mechanisms under practical environmental disturbances. In this work, a unified multiphysics model is established based on the constitutive equations of piezoelectric and magnetostrictive materials. Analytical expressions for the inverse magnetoelectric coefficient and acoustic resonance frequency are derived as functions of external stress, magnetic field, and temperature. Simulation results show that moderate stress and bias magnetic field enhance ME coupling efficiency, whereas temperature mainly induces linear frequency drift. Under the parameter-scan ranges and evaluation criteria defined in this work, the recommended combined condition for subsequent tuning-scheme validation is 20 MPa stress, 4000 A/m magnetic field, and 20 °C. Based on these findings, three frequency-tuning approaches DC-voltage tuning, capacitive loading, and integration of a phase-change material layer are further proposed, enabling controllable and wide-range frequency adjustment. The results provide quantitative guidelines for ME antenna design under complex environments and demonstrate clear potential for applications in micro-unmanned platforms and other constrained multiphysics scenarios.
{"title":"Tunable magnetoelectric antennas enabled by multi-physics synergistic regulation","authors":"Sijie Min, Kai Liu, Na Li, Zeshuo Jiao, Yiqun Zhang, Bin Zheng","doi":"10.1016/j.jmmm.2026.173831","DOIUrl":"10.1016/j.jmmm.2026.173831","url":null,"abstract":"<div><div>The demand for highly miniaturized antennas in micro-unmanned platforms has motivated the exploration of magnetoelectric (ME) antennas, which achieve sound-electric-magnetic energy conversion through the strong coupling between piezoelectric and magnetostrictive layers. Although ME antennas offer extreme size reduction by leveraging bulk acoustic wave resonance, their performance remains limited due to incomplete understanding of multi-physics coupling mechanisms under practical environmental disturbances. In this work, a unified multiphysics model is established based on the constitutive equations of piezoelectric and magnetostrictive materials. Analytical expressions for the inverse magnetoelectric coefficient and acoustic resonance frequency are derived as functions of external stress, magnetic field, and temperature. Simulation results show that moderate stress and bias magnetic field enhance ME coupling efficiency, whereas temperature mainly induces linear frequency drift. Under the parameter-scan ranges and evaluation criteria defined in this work, the recommended combined condition for subsequent tuning-scheme validation is 20 MPa stress, 4000 A/m magnetic field, and 20 °C. Based on these findings, three frequency-tuning approaches DC-voltage tuning, capacitive loading, and integration of a phase-change material layer are further proposed, enabling controllable and wide-range frequency adjustment. The results provide quantitative guidelines for ME antenna design under complex environments and demonstrate clear potential for applications in micro-unmanned platforms and other constrained multiphysics scenarios.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173831"},"PeriodicalIF":3.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035301","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}
Pub Date : 2026-01-16DOI: 10.1016/j.jmmm.2026.173846
H.H. Medina Chanduví , A.M. Mudarra Navarro , G. Távara Aponte , R.E. Zavala Sánchez , J.A. Roldán-López , K. Ferradas , L.A. Errico
We present a Density Functional Theory (DFT) based ab initio study of the structural, electronic, magnetic, and hyperfine properties of the semiconducting spinel-ferrite MgFe₂O₄. Calculations were performed using the all-electron Full-Potential Linearized Augmented Plane Wave (FP-LAPW) and the pseudopotential and plane-wave (PW-PP) methods in the frameworks of the Generalized Gradient Approximation (GGA) and GGA + U. To determine the lowest-energy structural and magnetic configuration of MgFe2O4, we examined various spin arrangements and cation distributions of Mg and Fe in the spinel lattice. Our results indicate that MgFe₂O₄ adopts an inverted antiferromagnetic structure. We also show that the energy necessary to reduce the inversion degree from 1 to 0.875 is smaller than those provided by the thermal treatments usually applied for the growth of the samples, showing that the formation of metastable phases with inversion degrees smaller than 1 is plausible, in agreement with the experimental results. Hyperfine interactions properties at Fe sites were obtained and compared to Mössbauer spectroscopy measurements at 4 K and 300 K, enabling a detailed characterization of the local Fe environments and gives support to our structural and magnetic model for MgFe2O4. Based on the results obtained for the bulk calculations, different (001) MgFe2O4 surface terminations were examined and we found that, after a strong surface reconstruction, the most stable termination is the one that exposes Mg, Fe, and O atoms. We show that the surface inversion degree predicted by DFT is lower than the bulk value, a result that is consistent with experimental results obtained in nanoparticles and that cationic inversion in the superficial layers plays a crucial role in the magnetic response of MgFe2O4 nanoparticles and thin films.
{"title":"DFT insight into the structural and magnetic properties of MgFe₂O₄ ferrite: Bulk and surface","authors":"H.H. Medina Chanduví , A.M. Mudarra Navarro , G. Távara Aponte , R.E. Zavala Sánchez , J.A. Roldán-López , K. Ferradas , L.A. Errico","doi":"10.1016/j.jmmm.2026.173846","DOIUrl":"10.1016/j.jmmm.2026.173846","url":null,"abstract":"<div><div>We present a Density Functional Theory (DFT) based ab initio study of the structural, electronic, magnetic, and hyperfine properties of the semiconducting spinel-ferrite MgFe₂O₄. Calculations were performed using the all-electron Full-Potential Linearized Augmented Plane Wave (FP-LAPW) and the pseudopotential and plane-wave (PW-PP) methods in the frameworks of the Generalized Gradient Approximation (GGA) and GGA + <em>U</em>. To determine the lowest-energy structural and magnetic configuration of MgFe<sub>2</sub>O<sub>4</sub>, we examined various spin arrangements and cation distributions of Mg and Fe in the spinel lattice. Our results indicate that MgFe₂O₄ adopts an inverted antiferromagnetic structure. We also show that the energy necessary to reduce the inversion degree from 1 to 0.875 is smaller than those provided by the thermal treatments usually applied for the growth of the samples, showing that the formation of metastable phases with inversion degrees smaller than 1 is plausible, in agreement with the experimental results. Hyperfine interactions properties at Fe sites were obtained and compared to Mössbauer spectroscopy measurements at 4 K and 300 K, enabling a detailed characterization of the local Fe environments and gives support to our structural and magnetic model for MgFe<sub>2</sub>O<sub>4</sub>. Based on the results obtained for the bulk calculations, different (001) MgFe<sub>2</sub>O<sub>4</sub> surface terminations were examined and we found that, after a strong surface reconstruction, the most stable termination is the one that exposes Mg, Fe, and O atoms. We show that the surface inversion degree predicted by DFT is lower than the bulk value, a result that is consistent with experimental results obtained in nanoparticles and that cationic inversion in the superficial layers plays a crucial role in the magnetic response of MgFe<sub>2</sub>O<sub>4</sub> nanoparticles and thin films.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173846"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035298","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}
Pub Date : 2026-01-16DOI: 10.1016/j.jmmm.2026.173848
A. El Boubekri , M. Sajieddine , M. Lassri , M. Sahlaoui , A. Razouk , H. Lassri , A. Essoumhi
Amorphous alloys with the composition Fe78−xCr2+xSi8B12 (x = 0–10 at. %) were produced by rapid quenching melt-spinning. X-ray diffraction confirmed their fully amorphous nature, while thermal analysis revealed glass transition and crystallization events, with the onset of crystallization shifting to higher temperatures as chromium content increased. Scanning electron microscopy showed uniform and defect-free surfaces, confirming compositional homogeneity across all samples. At the atomic scale, 57Fe Mössbauer spectroscopy provided insights into the local magnetic environment. The spectra exhibited broad and bimodal hyperfine field distributions, reflecting two of atomic surroundings: Fe-rich clusters and regions diluted by Cr, Si, and B. Increasing Cr content progressively reduced both the average hyperfine field and the Fe magnetic moment. These microscopic trends were echoed in bulk magnetic behavior. Hysteresis loops revealed soft ferromagnetic characteristics with low coercivity, and the saturation magnetization closely followed the Mössbauer-derived Fe moments. The correlations between local atomic order and magnetism highlight the dual role of chromium: it stabilizes the amorphous structure while tuning magnetic softness.
{"title":"Mössbauer study and magnetic properties of Fe78-xCr2+xSi8B12 amorphous ribbons","authors":"A. El Boubekri , M. Sajieddine , M. Lassri , M. Sahlaoui , A. Razouk , H. Lassri , A. Essoumhi","doi":"10.1016/j.jmmm.2026.173848","DOIUrl":"10.1016/j.jmmm.2026.173848","url":null,"abstract":"<div><div>Amorphous alloys with the composition Fe<sub>78−x</sub>Cr<sub>2+x</sub>Si<sub>8</sub>B<sub>12</sub> (<em>x</em> = 0–10 at. %) were produced by rapid quenching melt-spinning. X-ray diffraction confirmed their fully amorphous nature, while thermal analysis revealed glass transition and crystallization events, with the onset of crystallization shifting to higher temperatures as chromium content increased. Scanning electron microscopy showed uniform and defect-free surfaces, confirming compositional homogeneity across all samples. At the atomic scale, <sup>57</sup>Fe Mössbauer spectroscopy provided insights into the local magnetic environment. The spectra exhibited broad and bimodal hyperfine field distributions, reflecting two of atomic surroundings: Fe-rich clusters and regions diluted by Cr, Si, and B. Increasing Cr content progressively reduced both the average hyperfine field and the Fe magnetic moment. These microscopic trends were echoed in bulk magnetic behavior. Hysteresis loops revealed soft ferromagnetic characteristics with low coercivity, and the saturation magnetization closely followed the Mössbauer-derived Fe moments. The correlations between local atomic order and magnetism highlight the dual role of chromium: it stabilizes the amorphous structure while tuning magnetic softness.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173848"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035347","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}
Pub Date : 2026-01-16DOI: 10.1016/j.jmmm.2026.173853
Omar H. El-Talkhawy , Samy H. Aly , Sherif Yehia , Fatema Z. Mohammad
In this work, we present a mean-field study using the two-sublattice model to investigate the magnetothermal and magnetocaloric properties of Tb (Fe1-x Mnx)2 compounds with x = 0 and 0.12. Specifically, we have calculated the magnetization, heat capacity, entropy, isothermal entrop change ΔSm and adiabatic temperature change ∆Tad. This study investigates the aforementioned properties at temperatures up to 900 K and magnetic fields up to 5 T. Additionally, we report the relative cooling powers (RCP) in a 5 T field. We have used the Wien2k code to calculate the electron density of states (DOS) for TbFe2. The maximum values obtained, for TbFe2, for ΔSm, ∆Tad, RCP(S) and RCP(T) for a field change of 5 T are 2.37 J/mol. K, 3.05 K, 410 J/mol. and 1070 K2, respectively. The Curie temperatures of the compounds with x = 0 and x = 0.12 are 694 and 626 K respectively. The maximum magnetic entropy, in zero fields, for these two compounds is about 40 J/mol. K. The electronic γe = 0.018 J/mol. K2 for the x = 0 compound. The nature of the phase transition was analyzed, as well, using the universal curve and Belov-Arrott plots. The scaling exponent n is found to be fairly close to n = 2/3 for second order phase transitions described by the mean-field model. It has been confirmed that the transition is a second-order phase transition in both compounds.
{"title":"Magnetic Properties and Magnetocaloric Effect in Tb (Fe1-x Mnx)2 Compounds for x = 0, 0.12","authors":"Omar H. El-Talkhawy , Samy H. Aly , Sherif Yehia , Fatema Z. Mohammad","doi":"10.1016/j.jmmm.2026.173853","DOIUrl":"10.1016/j.jmmm.2026.173853","url":null,"abstract":"<div><div>In this work, we present a mean-field study using the two-sublattice model to investigate the magnetothermal and magnetocaloric properties of Tb (Fe<sub>1-x</sub> Mn<sub>x</sub>)<sub>2</sub> compounds with x = 0 and 0.12. Specifically, we have calculated the magnetization, heat capacity, entropy, isothermal entrop change ΔS<sub>m</sub> and adiabatic temperature change ∆T<sub>ad</sub>. This study investigates the aforementioned properties at temperatures up to 900 K and magnetic fields up to 5 T. Additionally, we report the relative cooling powers (RCP) in a 5 T field. We have used the Wien2k code to calculate the electron density of states (DOS) for TbFe<sub>2</sub>. The maximum values obtained, for TbFe<sub>2</sub>, for ΔS<sub>m</sub>, ∆T<sub>ad</sub>, RCP(S) and RCP(T) for a field change of 5 T are 2.37 J/mol. K, 3.05 K, 410 J/mol. and 1070 K<sup>2</sup>, respectively. The Curie temperatures of the compounds with x = 0 and x = 0.12 are 694 and 626 K respectively. The maximum magnetic entropy, in zero fields, for these two compounds is about 40 J/mol. K. The electronic γ<sub>e</sub> = 0.018 J/mol. K<sup>2</sup> for the x = 0 compound. The nature of the phase transition was analyzed, as well, using the universal curve and Belov-Arrott plots. The scaling exponent n is found to be fairly close to <em>n</em> = 2/3 for second order phase transitions described by the mean-field model. It has been confirmed that the transition is a second-order phase transition in both compounds.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173853"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035304","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}
We investigate the nonlinear spin dynamics of a frustrated Kagomé lattice subjected to a time-periodic magnetic field, focusing on the effects of Dzyaloshinskii–Moriya interaction (DMI), magnetic anisotropy and exchange coupling. Using numerical simulations of the Landau–Lifshitz–Gilbert equation, we analyze the evolution of spin oscillations via Poincaré surface sections and power spectral density across a wide parameter range. At low DMI, weak anisotropy, and small external field strengths, the system exhibits quasi-periodic oscillations governed primarily by exchange interactions. Increasing the DMI strength induces strong aperiodic behavior, with a clear transition to chaotic dynamics, particularly under moderate anisotropy. While strong easy-axis anisotropy tends to stabilize periodic orbits, sufficiently strong DMI can still drive the system into chaos. Furthermore, we show that external fields destabilize oscillations in weakly anisotropic regimes but have limited impact in the presence of strong anisotropy. We also compute the magnon dispersion relation and magnetic resonance (MR) spectra, revealing multi-peak structures at high DMI which indicate the presence of strong nonlinear spin-wave interactions. Our results highlight the critical role of DMI and anisotropy in shaping dynamical responses in Kagomé magnets, affecting the development of spintronic and magnonic devices.
{"title":"Nonlinearity in spin dynamics of frustrated Kagomé lattice system under harmonic perturbation","authors":"Saumen Acharjee, Arindam Boruah, Reeta Devi, Nimisha Dutta","doi":"10.1016/j.jmmm.2026.173852","DOIUrl":"10.1016/j.jmmm.2026.173852","url":null,"abstract":"<div><div>We investigate the nonlinear spin dynamics of a frustrated Kagomé lattice subjected to a time-periodic magnetic field, focusing on the effects of Dzyaloshinskii–Moriya interaction (DMI), magnetic anisotropy and exchange coupling. Using numerical simulations of the Landau–Lifshitz–Gilbert equation, we analyze the evolution of spin oscillations via Poincaré surface sections and power spectral density across a wide parameter range. At low DMI, weak anisotropy, and small external field strengths, the system exhibits quasi-periodic oscillations governed primarily by exchange interactions. Increasing the DMI strength induces strong aperiodic behavior, with a clear transition to chaotic dynamics, particularly under moderate anisotropy. While strong easy-axis anisotropy tends to stabilize periodic orbits, sufficiently strong DMI can still drive the system into chaos. Furthermore, we show that external fields destabilize oscillations in weakly anisotropic regimes but have limited impact in the presence of strong anisotropy. We also compute the magnon dispersion relation and magnetic resonance (MR) spectra, revealing multi-peak structures at high DMI which indicate the presence of strong nonlinear spin-wave interactions. Our results highlight the critical role of DMI and anisotropy in shaping dynamical responses in Kagomé magnets, affecting the development of spintronic and magnonic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173852"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035355","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}
Pub Date : 2026-01-16DOI: 10.1016/j.jmmm.2026.173850
Bo-Yu Song , Li-Quan Wang , Yong-Quan Han , Juan Cheng , Tao Chen , Xiang Jin , Jiao-Hong Huang
Room-temperature magnetic refrigeration is a new type of solid-state refrigeration technology. As refrigerants, La (Fe, Si)13-based alloys have become candidate refrigeration materials because of their considerable magnetocaloric effect and adjustable Curie temperature, but their inherent brittleness yields severe limitations. Selective laser melting (SLM) technology in additive manufacturing could solve the problems associated with the formation and processing of materials. In this study, La(Fe, Al, Si)13 alloys were prepared via SLM technology, and the effects of different scanning strategies on the surface morphology, microstructure, magnetocaloric properties and mechanical properties were systematically analysed. The results revealed that the content of the 1:13 main phase is highest in the sample formed through the interlayer rotation 67° scanning strategy, the maximum magnetic entropy change can reach 8.07 J/(kg · K), and the compressive strength and hardness are greatest. This strategy provides a shorter laser scanning path and easily achieves a consistent solidification rate, thus effectively reducing stress concentration, which is conducive to the application of magnetic refrigeration technology.
{"title":"Effects of different scanning strategies on the magnetocaloric effect and mechanical properties of La(Fe,Si)13-based alloys prepared by selective laser melting","authors":"Bo-Yu Song , Li-Quan Wang , Yong-Quan Han , Juan Cheng , Tao Chen , Xiang Jin , Jiao-Hong Huang","doi":"10.1016/j.jmmm.2026.173850","DOIUrl":"10.1016/j.jmmm.2026.173850","url":null,"abstract":"<div><div>Room-temperature magnetic refrigeration is a new type of solid-state refrigeration technology. As refrigerants, La (Fe, Si)<sub>13</sub>-based alloys have become candidate refrigeration materials because of their considerable magnetocaloric effect and adjustable Curie temperature, but their inherent brittleness yields severe limitations. Selective laser melting (SLM) technology in additive manufacturing could solve the problems associated with the formation and processing of materials. In this study, La(Fe, Al, Si)<sub>13</sub> alloys were prepared via SLM technology, and the effects of different scanning strategies on the surface morphology, microstructure, magnetocaloric properties and mechanical properties were systematically analysed. The results revealed that the content of the 1:13 main phase is highest in the sample formed through the interlayer rotation 67° scanning strategy, the maximum magnetic entropy change can reach 8.07 J/(kg · K), and the compressive strength and hardness are greatest. This strategy provides a shorter laser scanning path and easily achieves a consistent solidification rate, thus effectively reducing stress concentration, which is conducive to the application of magnetic refrigeration technology.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173850"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035296","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}
We systematically investigated the structural, electronic, and magnetic properties of zigzag silicene–germanene nanoribbons (zSiGeNRs) with various edge modifications using first-principles density functional theory. The results reveal that the ground-state properties of zSiGeNRs are highly sensitive to both the chemical composition and the symmetry of edge terminations. Homogeneous symmetric modifications (e.g., 2Cl–zSiGeNR–2Cl, 2F–zSiGeNR–2F, 2H–zSiGeNR–2H) exhibit antiferromagnetic metallic behavior, whereas homogeneous asymmetric ones (e.g., 2F–zSiGeNR–1F, 2Cl–zSiGeNR–1Cl) induce robust half-metallicity. Heterogeneous edge functionalizations further enhance tunability: symmetric configurations display narrow-gap semiconducting characteristics, while asymmetric ones yield half-metallic states, with the direction of edge asymmetry determining the metallic spin channel. The application of a transverse electric field enables reversible transitions between metallic, semiconducting, and half-metallic phases, demonstrating strong electric-field control. Certain asymmetric systems preserve half-metallicity under high fields, indicating excellent stability for spintronic applications. Additionally, width-dependent analysis demonstrates that quantum confinement and edge interactions govern electronic evolution, with asymmetric systems such as 2F–zSiGeNR–1F retaining half-metallicity across a broad width range (). The Si–Ge hybridization provides enhanced tunability compared to single-element nanoribbons, enabling band gap and spin polarization control via simple edge chemistry. These findings highlight that combining edge modification, external electric fields, and width engineering offers an effective route for tailoring the properties of zSiGeNRs. The observed field-tunable half-metallicity and Si-based compatibility make these nanoribbons promising candidates for next-generation spintronic and nanoelectronic devices.
{"title":"Tailoring electronic and magnetic properties of edge-functionalized silicene–germanene nanoribbons through first-principles simulations","authors":"Koussai Lazaar , Mohamed Barhoumi , Wissem Dimassi , Moncef Said","doi":"10.1016/j.jmmm.2026.173854","DOIUrl":"10.1016/j.jmmm.2026.173854","url":null,"abstract":"<div><div>We systematically investigated the structural, electronic, and magnetic properties of zigzag silicene–germanene nanoribbons (zSiGeNRs) with various edge modifications using first-principles density functional theory. The results reveal that the ground-state properties of zSiGeNRs are highly sensitive to both the chemical composition and the symmetry of edge terminations. Homogeneous symmetric modifications (e.g., 2Cl–zSiGeNR–2Cl, 2F–zSiGeNR–2F, 2H–zSiGeNR–2H) exhibit antiferromagnetic metallic behavior, whereas homogeneous asymmetric ones (e.g., 2F–zSiGeNR–1F, 2Cl–zSiGeNR–1Cl) induce robust half-metallicity. Heterogeneous edge functionalizations further enhance tunability: symmetric configurations display narrow-gap semiconducting characteristics, while asymmetric ones yield half-metallic states, with the direction of edge asymmetry determining the metallic spin channel. The application of a transverse electric field enables reversible transitions between metallic, semiconducting, and half-metallic phases, demonstrating strong electric-field control. Certain asymmetric systems preserve half-metallicity under high fields, indicating excellent stability for spintronic applications. Additionally, width-dependent analysis demonstrates that quantum confinement and edge interactions govern electronic evolution, with asymmetric systems such as 2F–zSiGeNR–1F retaining half-metallicity across a broad width range (<span><math><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>z</mi></mrow></msub><mo>=</mo><mn>6</mn><mo>−</mo><mn>14</mn></mrow></math></span>). The Si–Ge hybridization provides enhanced tunability compared to single-element nanoribbons, enabling band gap and spin polarization control via simple edge chemistry. These findings highlight that combining edge modification, external electric fields, and width engineering offers an effective route for tailoring the properties of zSiGeNRs. The observed field-tunable half-metallicity and Si-based compatibility make these nanoribbons promising candidates for next-generation spintronic and nanoelectronic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173854"},"PeriodicalIF":3.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975172","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}
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