Pub Date : 2026-03-15Epub Date: 2026-01-27DOI: 10.1016/j.jmmm.2026.173878
Yan Liu , Bin Lao , Yali Xie , Huali Yang , Xilai Bao , Huatao Jiang , Ruoan Zou , Pengfei Xin , Yao Ying , Run-Wei Li
Earlier demonstration of magnetic film-based functionalities on flexible substrates have highlighted the importance of perpendicular magnetic anisotropy (PMA) in flexible electronics. Here we studied magnetic anisotropic properties of flexible CoFeB/Pt multilayers with various structural parameters including substrate roughness, layer thickness, and stacking period, to anatomy the involved variables on PMA magnitude. A robust PMA is achieved in flexible CoFeB/Pt multilayers after improving surface roughness of flexible substrate, which is identical to that grown on rigid substrate. CoFeB and Pt thickness dependent magnetic anisotropy analysis confirms that the PMA is originated from CoFeB/Pt interface with a constant magnitude of 0.39 erg/cm2 regardless of the stack period. However, for Pt thickness below 1.5 nm, the interfacial PMA is gradually decrease, resulting in the magnetic easy axis shifts from perpendicular to planar orientation as the stacking period increases. After excluding possible influences from interfacial roughness and magnetic interlayer interactions, the reduction in PMA is attributed to limited orbital hybridization at the interface caused by the insufficient thickness of the Pt layer.
{"title":"Perpendicular magnetized flexible CoFeB/pt multilayers with pt thickness dependent interfacial magnetic anisotropy","authors":"Yan Liu , Bin Lao , Yali Xie , Huali Yang , Xilai Bao , Huatao Jiang , Ruoan Zou , Pengfei Xin , Yao Ying , Run-Wei Li","doi":"10.1016/j.jmmm.2026.173878","DOIUrl":"10.1016/j.jmmm.2026.173878","url":null,"abstract":"<div><div>Earlier demonstration of magnetic film-based functionalities on flexible substrates have highlighted the importance of perpendicular magnetic anisotropy (PMA) in flexible electronics. Here we studied magnetic anisotropic properties of flexible CoFeB/Pt multilayers with various structural parameters including substrate roughness, layer thickness, and stacking period, to anatomy the involved variables on PMA magnitude. A robust PMA is achieved in flexible CoFeB/Pt multilayers after improving surface roughness of flexible substrate, which is identical to that grown on rigid substrate. CoFeB and Pt thickness dependent magnetic anisotropy analysis confirms that the PMA is originated from CoFeB/Pt interface with a constant magnitude of 0.39 erg/cm<sup>2</sup> regardless of the stack period. However, for Pt thickness below 1.5 nm, the interfacial PMA is gradually decrease, resulting in the magnetic easy axis shifts from perpendicular to planar orientation as the stacking period increases. After excluding possible influences from interfacial roughness and magnetic interlayer interactions, the reduction in PMA is attributed to limited orbital hybridization at the interface caused by the insufficient thickness of the Pt layer.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173878"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076817","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 : 2026-03-15Epub Date: 2026-02-09DOI: 10.1016/j.jmmm.2026.173920
Y. Errouyessi , M. Lassri , S. El Ouahbi , L. Bessais , B. Manoun , H. Lassri , R. Moubah
This study explores the magnetic and magnetocaloric properties of fayalite. While classical magnetization measurements at a magnetic field of 0.01 T reveal the existence of only one transition from an inclined antiferromagnetic state to a collinear antiferromagnetic state at 30 K. Magnetic entropy (-ΔSm) across different temperatures and magnetic fields, reveals the existence of two well defined peaks corresponding to two magnetic transitions. One transition located at the Critical Temperature (TCr) around 30 K, and a second transition located at Néel temperature (TN) around 70 K marks the change from a collinear antiferromagnetic state to a paramagnetic state. This latter transition is not visible in the conventional magnetization at low fields versus temperature measurements. The phase transition induced by magnetic fields is identified as second order based on Arrott plots. The relative cooling power (RCP) was found to depend on the magnetic field according to a power law. These results demonstrate that the magnetocaloric effect is a particularly effective probe for detecting and studying complex magnetic transitions.
{"title":"Unveiling magnetic transition in Fe2SiO4 fayalites via magnetocaloric effect","authors":"Y. Errouyessi , M. Lassri , S. El Ouahbi , L. Bessais , B. Manoun , H. Lassri , R. Moubah","doi":"10.1016/j.jmmm.2026.173920","DOIUrl":"10.1016/j.jmmm.2026.173920","url":null,"abstract":"<div><div>This study explores the magnetic and magnetocaloric properties of <span><math><msub><mi>Fe</mi><mn>2</mn></msub><msub><mi>SiO</mi><mn>4</mn></msub></math></span> fayalite. While classical magnetization measurements at a magnetic field of 0.01 T reveal the existence of only one transition from an inclined antiferromagnetic state to a collinear antiferromagnetic state at 30 K. Magnetic entropy (<em>-ΔS</em><sub><em>m</em></sub>) across different temperatures and magnetic fields, reveals the existence of two well defined peaks corresponding to two magnetic transitions. One transition located at the Critical Temperature (<em>T</em><sub><em>Cr</em></sub>) around 30 K, and a second transition located at Néel temperature (<em>T</em><sub><em>N</em></sub>) around 70 K marks the change from a collinear antiferromagnetic state to a paramagnetic state. This latter transition is not visible in the conventional magnetization at low fields versus temperature measurements. The phase transition induced by magnetic fields is identified as second order based on Arrott plots. The relative cooling power (<em>RCP</em>) was found to depend on the magnetic field according to a power law. These results demonstrate that the magnetocaloric effect is a particularly effective probe for detecting and studying complex magnetic transitions.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173920"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185904","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 : 2026-03-15Epub Date: 2026-01-24DOI: 10.1016/j.jmmm.2026.173866
Pengning Zhang , Kuncheng Li , Lihua Mu , Ningwei Chen , Jian Zhang , Jia Zou
Modeling the hysteresis characteristics of power-transformer cores under dc bias is of critical importance for safe and stable equipment operation. Although existing Jiles–Atherton (J–A) models can deliver acceptable accuracy, they generally require extensive experimental data to calibrate bias-dependent coefficients and are prone to numerical oscillations under strong bias. Within the Energetic hysteresis framework, the dc bias field is introduced directly into the energy-barrier function and analytical coupling relations are derived among the saturation coefficient, the asymmetric-loss coefficient, and the remanence offset. A hybrid finite-difference scheme is further employed to solve simultaneously the rate of change of magnetic induction and the loss distribution, while a particle-swarm optimization algorithm is adopted for parameter identification. The proposed model achieves high-accuracy, high-stability predictions of hysteresis loops and losses under dc bias conditions. Experimental results demonstrate that the model reproduces the asymmetric features of hysteresis loops at various bias levels, with computed losses in excellent agreement with measured values, confirming its validity and engineering applicability.
{"title":"Modeling of asymmetric hysteresis in silicon steel sheets under DC bias and experimental verification","authors":"Pengning Zhang , Kuncheng Li , Lihua Mu , Ningwei Chen , Jian Zhang , Jia Zou","doi":"10.1016/j.jmmm.2026.173866","DOIUrl":"10.1016/j.jmmm.2026.173866","url":null,"abstract":"<div><div>Modeling the hysteresis characteristics of power-transformer cores under dc bias is of critical importance for safe and stable equipment operation. Although existing Jiles–Atherton (J–A) models can deliver acceptable accuracy, they generally require extensive experimental data to calibrate bias-dependent coefficients and are prone to numerical oscillations under strong bias. Within the Energetic hysteresis framework, the dc bias field is introduced directly into the energy-barrier function and analytical coupling relations are derived among the saturation coefficient, the asymmetric-loss coefficient, and the remanence offset. A hybrid finite-difference scheme is further employed to solve simultaneously the rate of change of magnetic induction and the loss distribution, while a particle-swarm optimization algorithm is adopted for parameter identification. The proposed model achieves high-accuracy, high-stability predictions of hysteresis loops and losses under dc bias conditions. Experimental results demonstrate that the model reproduces the asymmetric features of hysteresis loops at various bias levels, with computed losses in excellent agreement with measured values, confirming its validity and engineering applicability.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173866"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076818","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 : 2026-03-15Epub Date: 2026-02-03DOI: 10.1016/j.jmmm.2026.173881
Hala Siddiq
Spintronics is an advanced technology that utilizes electron spin to enable faster data transfer, processing, and storage. Therefore, in this context, here the electronic, magnetic, transport, mechanical, and thermodynamic characteristics of halide double perovskites Na2MoZ6 (Z = Cl, Br, I) are investigated by Wien2K and BoltzTraP codes. The structural optimization, formation energy, and phonon dispersion band structures are calculated to confirm the thermodynamic and lattice dynamic stability. The band structure analysis for the spin-up and spin-down configurations, along with the spin polarization density and integer magnetic moments, shows the half-metallic ferromagnetism and 100% spin polarization. The nature of ferromagnetism has been studied by the hybridization of the density of states, exchange constants, crystal field, and exchange energies.
The double exchange process also evidences the stability of ferromagnetism due to the lowering of the energy of the studied system and distribution of magnetic moments from Mo to nonmagnetic sites. Moreover, the large Seebeck coefficient, electrical conductivity, and low thermal conductivity were noticed, which enhanced the figure of merit (ZT). Mechanical behavior has been observed, which confirms the ductile and anisotropic nature. The large hardness, Debye temperature, melting temperature, and ultralow lattice thermal conductivity. Therefore, the above findings highly recommend these materials for spintronic and green energy devices.
{"title":"Investigation of Room Temperature Ferromagnetism, Mechanical and Thermoelectric Aspects of Na2MoZ6 (Z = Cl, Br, I) for Spintronic Applications","authors":"Hala Siddiq","doi":"10.1016/j.jmmm.2026.173881","DOIUrl":"10.1016/j.jmmm.2026.173881","url":null,"abstract":"<div><div>Spintronics is an advanced technology that utilizes electron spin to enable faster data transfer, processing, and storage. Therefore, in this context, here the electronic, magnetic, transport, mechanical, and thermodynamic characteristics of halide double perovskites Na<sub>2</sub>MoZ<sub>6</sub> (Z = Cl, Br, I) are investigated by Wien2K and BoltzTraP codes. The structural optimization, formation energy, and phonon dispersion band structures are calculated to confirm the thermodynamic and lattice dynamic stability. The band structure analysis for the spin-up and spin-down configurations, along with the spin polarization density and integer magnetic moments, shows the half-metallic ferromagnetism and 100% spin polarization. The nature of ferromagnetism has been studied by the hybridization of the density of states, exchange constants, crystal field, and exchange energies.</div><div>The double exchange process also evidences the stability of ferromagnetism due to the lowering of the energy of the studied system and distribution of magnetic moments from Mo to nonmagnetic sites. Moreover, the large Seebeck coefficient, electrical conductivity, and low thermal conductivity were noticed, which enhanced the figure of merit (ZT). Mechanical behavior has been observed, which confirms the ductile and anisotropic nature. The large hardness, Debye temperature, melting temperature, and ultralow lattice thermal conductivity. Therefore, the above findings highly recommend these materials for spintronic and green energy devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173881"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185801","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}
<div><div>Single crystals of spinel Fe<span><math><msub><mrow></mrow><mrow><mn>3</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Mn<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> were prepared by the flux method using a solvent based on Bi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Mo<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<sub>12</sub>-B<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>-Na<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O with the addition of gallium oxide Ga<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>. The structural features of the obtained samples were studied by powder and single crystal X-ray diffraction analysis. According to EDX data, the obtained Fe<span><math><msub><mrow></mrow><mrow><mn>3</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Mn<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> crystals contain gallium in the amount of 12% per formula unit. Differential scanning calorimetry, specific heat study and temperature and field dependences of magnetization of the obtained single crystal showed a significant reduction of the ferrimagnetic phase transition (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub></math></span> = 380 K) relative the parent Fe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>MnO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> compound (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub></math></span> = 560–580 K). The observed feature is, to a large extent, affected by the Fe/Mn/Ga ratio and demonstrates the possibility of the tuning the ferrimagnetic transition temperature over a wide temperature range. The flux technique for the single crystals synthesis enables precise variation of the Ga, Mn and Fe concentration in the (Fe,Mn,Ga)<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> allowing one to create the material with the needed magnetic properties. The obtained spinel compound was studied in a wide temperature range: 300–770 K by DSC and 4.2–600 K by magnetization measurements. Along with the high-temperature ferrimagnetic phase transition, anomalies of the temperature dependence of the magnetization in small fields (about <span><math><mi>H</mi></math></span> = 50–100 Oe) accompanied by significant thermal hysteresis were detected in the ordered phase at much lower temperatures about <span><ma
{"title":"Tunable magnetic properties of (Fe,Mn,Ga)3O4 spinel solid solution","authors":"N.A. Belskaya , M.S. Molokeev , D.A. Velikanov , A.L. Sukhachev , E.I. Pogorel’tsev , A.V. Kartashev , D. Kokh , E.V. Eremin , R.G. Batulin , M.A. Cherosov , E.M. Moshkina","doi":"10.1016/j.jmmm.2026.173900","DOIUrl":"10.1016/j.jmmm.2026.173900","url":null,"abstract":"<div><div>Single crystals of spinel Fe<span><math><msub><mrow></mrow><mrow><mn>3</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Mn<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> were prepared by the flux method using a solvent based on Bi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Mo<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<sub>12</sub>-B<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>-Na<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O with the addition of gallium oxide Ga<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>. The structural features of the obtained samples were studied by powder and single crystal X-ray diffraction analysis. According to EDX data, the obtained Fe<span><math><msub><mrow></mrow><mrow><mn>3</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Mn<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> crystals contain gallium in the amount of 12% per formula unit. Differential scanning calorimetry, specific heat study and temperature and field dependences of magnetization of the obtained single crystal showed a significant reduction of the ferrimagnetic phase transition (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub></math></span> = 380 K) relative the parent Fe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>MnO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> compound (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub></math></span> = 560–580 K). The observed feature is, to a large extent, affected by the Fe/Mn/Ga ratio and demonstrates the possibility of the tuning the ferrimagnetic transition temperature over a wide temperature range. The flux technique for the single crystals synthesis enables precise variation of the Ga, Mn and Fe concentration in the (Fe,Mn,Ga)<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> allowing one to create the material with the needed magnetic properties. The obtained spinel compound was studied in a wide temperature range: 300–770 K by DSC and 4.2–600 K by magnetization measurements. Along with the high-temperature ferrimagnetic phase transition, anomalies of the temperature dependence of the magnetization in small fields (about <span><math><mi>H</mi></math></span> = 50–100 Oe) accompanied by significant thermal hysteresis were detected in the ordered phase at much lower temperatures about <span><ma","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173900"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185805","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 : 2026-03-15Epub Date: 2026-02-10DOI: 10.1016/j.jmmm.2026.173907
Longtao Hou , Yuzhen Dong , Mikalai A. Zhurauski , Tong Zhang , Mubashar Mahmood , Linsheng Yu , Hassan Murtaza , Muhammad Khan , Ke Zhang , Jiupeng Zhao , Yao Li
Magnetorheological (MR) fluids are promising smart materials with versatile applications in various fields. However, these fluids still face limitations, such as poor sedimentation stability and the loss of their MR performance over time. Herein, we developed polydopamine (PDA) armor on carbonyl iron (CI) particles through a facile dispersion polymerization to overcome these limitations. The structural and morphological characteristics of the synthesized CI@PDA particles were investigated using scanning electron microscopy (SEM) & energy dispersive spectroscopy (EDS), while their improved oxidation resistance and stable magnetic properties were validated by thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM), respectively. Rheological evaluation of the CI@PDA-based fluids revealed that the PDA-coated CI particles provide enhanced MR performance compared to pristine CI, with tunability governed by synthesis parameters. Furthermore, the sedimentation test confirmed superior anti-settling behavior for all PDA-modified samples. Additional comparisons using SiO2 and Fe3O4 additives further supported the improved performance of the PDA-modified system. Overall, these findings offer a promising pathway to develop next-generation MR fluids with enhanced durability and self-adaptive behavior.
{"title":"Bio-inspired polydopamine armor on carbonyl Iron via supramolecular self-assembly for anti-sedimentation and self-adaptive magnetorheological fluids","authors":"Longtao Hou , Yuzhen Dong , Mikalai A. Zhurauski , Tong Zhang , Mubashar Mahmood , Linsheng Yu , Hassan Murtaza , Muhammad Khan , Ke Zhang , Jiupeng Zhao , Yao Li","doi":"10.1016/j.jmmm.2026.173907","DOIUrl":"10.1016/j.jmmm.2026.173907","url":null,"abstract":"<div><div>Magnetorheological (MR) fluids are promising smart materials with versatile applications in various fields. However, these fluids still face limitations, such as poor sedimentation stability and the loss of their MR performance over time. Herein, we developed polydopamine (PDA) armor on carbonyl iron (CI) particles through a facile dispersion polymerization to overcome these limitations. The structural and morphological characteristics of the synthesized CI@PDA particles were investigated using scanning electron microscopy (SEM) & energy dispersive spectroscopy (EDS), while their improved oxidation resistance and stable magnetic properties were validated by thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM), respectively. Rheological evaluation of the CI@PDA-based fluids revealed that the PDA-coated CI particles provide enhanced MR performance compared to pristine CI, with tunability governed by synthesis parameters. Furthermore, the sedimentation test confirmed superior anti-settling behavior for all PDA-modified samples. Additional comparisons using SiO<sub>2</sub> and Fe<sub>3</sub>O<sub>4</sub> additives further supported the improved performance of the PDA-modified system. Overall, these findings offer a promising pathway to develop next-generation MR fluids with enhanced durability and self-adaptive behavior.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173907"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185900","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 : 2026-03-15Epub Date: 2026-02-09DOI: 10.1016/j.jmmm.2026.173910
Nuray Kup Aylikci , Dursun Ekren , Volkan Aylikci , Mehmet Eyyuphan Yakinci
A rapid and cost-effective gram-scale synthesis of functionalized iron oxide (Fe3O4) nanoparticles were synthesized through a modified polyol method using only economically feasible FeCl3 as the iron precursor. Various ethylene glycol compounds (MEG, DEG, PEG300, PEG400, PEG1500, PEG6000) were served as solvents, reducing agents, and capping agents, with the reduction time significantly minimized to one hour at 180 °C. Rietveld refinement and XPS analysis confirmed the formation of a pure magnetite phase with an inverse spinel crystal structure across all samples. Magnetic characterization was conducted at 300 K and analysed via Langevin and Law of Approach to Saturation (LAS) modelling. While the effective anisotropy energy was found to be lower than the thermal energy, the presence of non-zero coercivity and relatively large crystallite sizes in certain samples—most notably the DEG-functionalized form (176.5 nm)—indicates that the nanoparticles exhibit features approaching the superparamagnetic regime rather than ideal superparamagnetism. Consequently, the magnetic response is characterized as a superparamagnetic-like behaviour. The MEG-functionalized nanoparticles demonstrated the highest saturation magnetization (Ms = 70.72 emu/g), which is attributed to a high magnetic moment per core despite the presence of a magnetic dead layer. Morphological analysis revealed nearly spherical and cauliflower-like structures, with particle sizes ranging from 10.09 nm to 199.53 nm. These variations are explained by the transition between brush and mushroom conformations of the ethylene glycol chains, which influence steric repulsion and particle growth during nucleation. This study provides a practical and scalable framework for producing high-magnetization iron oxide nanoparticles suitable for drug delivery, radar absorption, catalysis, and imaging technologies.
{"title":"Facile gram-scale synthesis of Fe3O4 nanoparticles approaching the superparamagnetic regime: Influence of polyol chain length","authors":"Nuray Kup Aylikci , Dursun Ekren , Volkan Aylikci , Mehmet Eyyuphan Yakinci","doi":"10.1016/j.jmmm.2026.173910","DOIUrl":"10.1016/j.jmmm.2026.173910","url":null,"abstract":"<div><div>A rapid and cost-effective gram-scale synthesis of functionalized iron oxide (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles were synthesized through a modified polyol method using only economically feasible FeCl<sub>3</sub> as the iron precursor. Various ethylene glycol compounds (MEG, DEG, PEG300, PEG400, PEG1500, PEG6000) were served as solvents, reducing agents, and capping agents, with the reduction time significantly minimized to one hour at 180 °C. Rietveld refinement and XPS analysis confirmed the formation of a pure magnetite phase with an inverse spinel crystal structure across all samples. Magnetic characterization was conducted at 300 K and analysed via Langevin and Law of Approach to Saturation (LAS) modelling. While the effective anisotropy energy was found to be lower than the thermal energy, the presence of non-zero coercivity and relatively large crystallite sizes in certain samples—most notably the DEG-functionalized form (176.5 nm)—indicates that the nanoparticles exhibit features approaching the superparamagnetic regime rather than ideal superparamagnetism. Consequently, the magnetic response is characterized as a superparamagnetic-like behaviour. The MEG-functionalized nanoparticles demonstrated the highest saturation magnetization (M<sub>s</sub> = 70.72 emu/g), which is attributed to a high magnetic moment per core despite the presence of a magnetic dead layer. Morphological analysis revealed nearly spherical and cauliflower-like structures, with particle sizes ranging from 10.09 nm to 199.53 nm. These variations are explained by the transition between brush and mushroom conformations of the ethylene glycol chains, which influence steric repulsion and particle growth during nucleation. This study provides a practical and scalable framework for producing high-magnetization iron oxide nanoparticles suitable for drug delivery, radar absorption, catalysis, and imaging technologies.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"642 ","pages":"Article 173910"},"PeriodicalIF":3.0,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185903","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 : 2026-03-01Epub Date: 2026-01-06DOI: 10.1016/j.jmmm.2026.173810
Norah Algethami
A recent article systematically investigated the electronic behavior, Curie temperature, spin polarization, magnetic, thermoelectric, mechanical, and thermodynamic aspects of Ba2XWO6 (X = Fe, Mn, Co, Ni) by the use of Wien2K and BoltzTraP codes. The comparatively larger energy release in ferromagnetic states than in antiferromagnetic states (A-, C-, G-) ensures the stability of FM states. Moreover, the tolerance factor, formation energy, and the phonon dispersion band structures confirm the ferromagnetic states' structural, thermodynamic, and dynamic stability. The empirical relation of Heisenberg and band structure analysis measures the ferromagnetism above room temperature and 100 % spin polarization (SP = 1.0). Furthermore, the hybridization of individual density of atomic states, double exchange, and exchange are also briefly focused on the nature of ferromagnetism and the exchange function of 3d/4d electrons' spin. Ferromagnetism is caused by the exchange of electrons, not by magnetic ion clustering, which has been revealed by shifting the magnetic moment from X (5.0 to 2.0) μB and W sites to Ba and O sites. In addition, the effect of thermal conductivity, lattice vibration, Seebeck coefficient, and electrical conductivity on the spin degree of freedom of electrons has been explored for both spin (↑) and spin (↓) arrangements. The power factor and figure of merit (1.58, 1.37, 1.34, 1.33) calculate the performance of these DPs for energy harvesting. Finally, the elastic constants satisfy the Born criteria and show a ductile nature. The large melting and Debye temperature, hardness, and minimum lattice thermal conductivity have also increased the importance of these materials for spintronic applications.
{"title":"First principle study of physical aspect and role of 3d/4d electrons in ferromagnetism in Ba2XWO6 (X = Fe, Mn, Co, Ni) for spintronic applications","authors":"Norah Algethami","doi":"10.1016/j.jmmm.2026.173810","DOIUrl":"10.1016/j.jmmm.2026.173810","url":null,"abstract":"<div><div>A recent article systematically investigated the electronic behavior, Curie temperature, spin polarization, magnetic, thermoelectric, mechanical, and thermodynamic aspects of Ba<sub>2</sub>XWO<sub>6</sub> (X = Fe, Mn, Co, Ni) by the use of Wien2K and BoltzTraP codes. The comparatively larger energy release in ferromagnetic states than in antiferromagnetic states (A-, C-, G-) ensures the stability of FM states. Moreover, the tolerance factor, formation energy, and the phonon dispersion band structures confirm the ferromagnetic states' structural, thermodynamic, and dynamic stability. The empirical relation of Heisenberg and band structure analysis measures the ferromagnetism above room temperature and 100 % spin polarization (SP = 1.0). Furthermore, the hybridization of individual density of atomic states, double exchange, and exchange are also briefly focused on the nature of ferromagnetism and the exchange function of 3d/4d electrons' spin. Ferromagnetism is caused by the exchange of electrons, not by magnetic ion clustering, which has been revealed by shifting the magnetic moment from X (5.0 to 2.0) μ<sub>B</sub> and W sites to Ba and O sites. In addition, the effect of thermal conductivity, lattice vibration, Seebeck coefficient, and electrical conductivity on the spin degree of freedom of electrons has been explored for both spin (↑) and spin (↓) arrangements. The power factor and figure of merit (1.58, 1.37, 1.34, 1.33) calculate the performance of these DPs for energy harvesting. Finally, the elastic constants satisfy the Born criteria and show a ductile nature. The large melting and Debye temperature, hardness, and minimum lattice thermal conductivity have also increased the importance of these materials for spintronic applications.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173810"},"PeriodicalIF":3.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941219","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 : 2026-03-01Epub Date: 2026-01-22DOI: 10.1016/j.jmmm.2026.173861
Tao Liu , Shilin Li , Yu Zhang , Huacheng Tong , Youhong Peng , Yaodong Wu , Suo Bai , Yuqing Xing , Da Xu , Shunshun Zhang , Yegang Wang , Lanhao Dong , Mengchao Zhang , Shengrong Zhang , Yanli Liu , Sitian Cai , Qiong Wu , Ming Yue , Haifeng Du , Jin Tang
Nd-Fe-B permanent magnets, which are essential for advanced technologies due to their superior magnetic properties, are facing growing demands for reliability as their applications diversify into critical sectors such as new energy vehicles and robotics. Corrosion resistance, critical to ensuring their functional longevity, remains a key challenge. This study addresses this by using a Zn-Li-Mn alloy for grain boundary diffusion (GBD), which enables simultaneous enhancement of coercivity and anti-corrosion performance in sintered Nd-Fe-B. After treatment, coercivity increased by 1.25 kOe with minimal remanence loss (<0.5%), while sixty-day salt immersion corrosion tests (immersed in a 3.5 wt% NaCl) showed a 70% reduction in mass loss and a corrosion potential shift from −0.80 V to −0.50 V, demonstrating significantly enhanced degradation resistance. Multiscale analysis (XRD/EPMA/TEM) revealed that multi-element co-diffusion modifies grain boundaries through dual mechanisms: coordinated modification of grain boundaries to enhance coercivity, combined with Zn/Mn segregation that forms a dense oxide film that passivates corrosion pathways. This non-rare-earth GBD strategy provides a scalable, cost-effective solution to optimize magnet durability without relying on expensive rare-earth additives, delivering transformative potential for industrial applications requiring high-performance sustainable materials.
{"title":"Effect of Zn-Li-Mn grain boundary diffusion on magnetic and corrosion resistance of sintered Nd-Fe-B magnets","authors":"Tao Liu , Shilin Li , Yu Zhang , Huacheng Tong , Youhong Peng , Yaodong Wu , Suo Bai , Yuqing Xing , Da Xu , Shunshun Zhang , Yegang Wang , Lanhao Dong , Mengchao Zhang , Shengrong Zhang , Yanli Liu , Sitian Cai , Qiong Wu , Ming Yue , Haifeng Du , Jin Tang","doi":"10.1016/j.jmmm.2026.173861","DOIUrl":"10.1016/j.jmmm.2026.173861","url":null,"abstract":"<div><div>Nd-Fe-B permanent magnets, which are essential for advanced technologies due to their superior magnetic properties, are facing growing demands for reliability as their applications diversify into critical sectors such as new energy vehicles and robotics. Corrosion resistance, critical to ensuring their functional longevity, remains a key challenge. This study addresses this by using a Zn-Li-Mn alloy for grain boundary diffusion (GBD), which enables simultaneous enhancement of coercivity and anti-corrosion performance in sintered Nd-Fe-B. After treatment, coercivity increased by 1.25 kOe with minimal remanence loss (<0.5%), while sixty-day salt immersion corrosion tests (immersed in a 3.5 wt% NaCl) showed a 70% reduction in mass loss and a corrosion potential shift from −0.80 V to −0.50 V, demonstrating significantly enhanced degradation resistance. Multiscale analysis (XRD/EPMA/TEM) revealed that multi-element co-diffusion modifies grain boundaries through dual mechanisms: coordinated modification of grain boundaries to enhance coercivity, combined with Zn/Mn segregation that forms a dense oxide film that passivates corrosion pathways. This non-rare-earth GBD strategy provides a scalable, cost-effective solution to optimize magnet durability without relying on expensive rare-earth additives, delivering transformative potential for industrial applications requiring high-performance sustainable materials.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173861"},"PeriodicalIF":3.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074401","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 : 2026-03-01Epub Date: 2026-01-18DOI: 10.1016/j.jmmm.2026.173844
Haoze Ma , Jie Wang , Fan Li , Li Sun , Xiaogang Ma , Bin Han
To quantify the effect of surface quality on flow performance and achieve cost-performance co-optimization in magnetically polished TA16 slender tubes, this study proposes an integrated evaluation method combining fluid simulation with AHP-WSM. A surface roughness-flow performance mapping model was established to analyze the influence of Ra (0.29 μm to 2.79 μm) on flow velocity, pressure loss, and thermal conductivity. Results show that reducing Ra from 2.79 to 0.29 μm increases peak outlet velocity from 3.724 to 3.744 m·s−1, decreases total pressure loss from 6003.38 to 5739.23 Pa, and lowers mean outlet temperature from 88.546 to 88.516 °C, with sensitivity order: pressure loss> flow velocity > temperature. Multi-objective optimization via analytic hierarchy process-weighted scoring method (AHP-WSM) identifies Ra from 0.45 μm to 0.75 μm as the Pareto-optimal range. This approach provides an economic-performance balanced decision basis for predicting pipeline performance and controlling surface quality in precision tubing.
{"title":"Surface quality evaluation method for TA16 slender tubes via magnetic abrasive finishing based on fluid simulation and AHP-WSM approach","authors":"Haoze Ma , Jie Wang , Fan Li , Li Sun , Xiaogang Ma , Bin Han","doi":"10.1016/j.jmmm.2026.173844","DOIUrl":"10.1016/j.jmmm.2026.173844","url":null,"abstract":"<div><div>To quantify the effect of surface quality on flow performance and achieve cost-performance co-optimization in magnetically polished TA16 slender tubes, this study proposes an integrated evaluation method combining fluid simulation with AHP-WSM. A surface roughness-flow performance mapping model was established to analyze the influence of <em>R</em><sub><em>a</em></sub> (0.29 μm to 2.79 μm) on flow velocity, pressure loss, and thermal conductivity. Results show that reducing <em>R</em><sub><em>a</em></sub> from 2.79 to 0.29 μm increases peak outlet velocity from 3.724 to 3.744 m·s<sup>−1</sup>, decreases total pressure loss from 6003.38 to 5739.23 Pa, and lowers mean outlet temperature from 88.546 to 88.516 °C, with sensitivity order: pressure loss> flow velocity > temperature. Multi-objective optimization via analytic hierarchy process-weighted scoring method (AHP-WSM) identifies <em>R</em><sub><em>a</em></sub> from 0.45 μm to 0.75 μm as the Pareto-optimal range. This approach provides an economic-performance balanced decision basis for predicting pipeline performance and controlling surface quality in precision tubing.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"641 ","pages":"Article 173844"},"PeriodicalIF":3.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035307","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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