Journal of Magnetism and Magnetic Materials最新文献

{"title":"In silico separation of magnetic nanoparticles from linear flow: A parametric study","authors":"N. Maniotis","doi":"10.1016/j.jmmm.2025.173460","DOIUrl":"10.1016/j.jmmm.2025.173460","url":null,"abstract":"<div><div>Magnetic separation of nanoparticles from water offers a promising approach for advanced water treatment, particularly for removing contaminants bound to functionalized magnetic carriers. This study presents an in silico investigation of magnetic nanoparticles capture from linear laminar flow using permanent magnets, modeled with COMSOL Multiphysics. A coupled simulation framework combines multiphysics modules to simulate the trajectories of 100 non-interacting nanoparticles suspended in water. Parametric analysis focuses on the influence of magnet-to-pipe distance, flow rate, and nanoparticle magnetization. Recognizing that magnetic nanoparticles often exhibit reduced magnetization due to size, surface, and shape effects, simulations include various fractions of the saturation magnetization rather than assuming full saturation. Magnetic field gradients are computed to evaluate magnetic forces, which are balanced against hydrodynamic drag to determine particle trajectories and separation efficiency. Results show that proximity of the magnets and increased effective magnetization significantly enhance particle capture, while higher flow rates reduce separation efficiency. This study offers a comprehensive assessment of the magnetic and hydrodynamic factors governing magnetic nanoparticles removal in flowing systems. The findings inform the design of efficient, scalable magnetic separation systems for water purification and environmental remediation applications.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173460"},"PeriodicalIF":3.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907770","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":"Thallium substitution effects on Co valence states and room-temperature ferromagnetism in co-doped In2O3: Experimental and machine-learning insights","authors":"Asuna Hagiya ,&nbsp;Toa Asakura ,&nbsp;Taketo Sekiya ,&nbsp;Takashi Kataoka ,&nbsp;Keiji Komatsu ,&nbsp;Keisuke Sato","doi":"10.1016/j.jmmm.2025.173450","DOIUrl":"10.1016/j.jmmm.2025.173450","url":null,"abstract":"&lt;div&gt;&lt;div&gt;We systematically investigate the effects of thallium (Tl) substitution in Co-doped indium oxide (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1.9&lt;/mn&gt;&lt;mo&gt;-&lt;/mo&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;/mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0.1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), focusing on its influence on Co valence states and magnetic properties. X-ray diffraction (XRD) confirmed that the bixbyite structure was preserved across a wide Tl composition range (&lt;em&gt;x&lt;/em&gt; = 0.0–0.6). X-ray photoelectron spectroscopy (XPS) revealed that Tl incorporation increased the &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;/&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; ratio before annealing. Vacuum annealing induced partial reduction of &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; to &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, but higher Tl substitution led to weaker enhancement of ferromagnetic order. Magnetization measurements showed that the pristine (&lt;em&gt;x&lt;/em&gt; = 0.0) composition transformed from a paramagnetic to a room-temperature ferromagnetic state upon annealing, while higher Tl content systematically weakened ferromagnetism. These results suggest that the larger ionic radius of &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; modifies crystal-field environments and magnetic exchange interactions, promoting &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; formation yet suppressing long-range ferromagnetism. A machine-learning model using ridge regression predicted the &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; ratio and room-temperature ferromagnetism (RTF) based on ionic radius and ionization energy with high accuracy (R&lt;sup&gt;2&lt;/sup&gt; ≥ 0.85). Predictions for hypothetical dopants in &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1.6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mrow&gt;&lt;mn&gt;0.3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0.1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; suggested rare-earth elements such as Pr, Lu, Ce and Nd could enhance &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; content and ferromagnetic properties. This study highlights how ionic size and ionization energy influence valence states and magnetism in &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;-based diluted magnetic semiconductors, demons","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173450"},"PeriodicalIF":3.0,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Ca2+ doping on Sr2-xCaxCrOsO6 physical behavior (x = 0, 0.5) for energy and spintronic applications","authors":"Y. El-harrar,&nbsp;R. Masrour,&nbsp;M. Hamedoun,&nbsp;J. Kharbach,&nbsp;A. Rezzouk,&nbsp;N. Benzakour,&nbsp;K. Bouslykhane","doi":"10.1016/j.jmmm.2025.173441","DOIUrl":"10.1016/j.jmmm.2025.173441","url":null,"abstract":"<div><div>Using ab initio calculations and Monte Carlo simulations, we investigate the electronic, optical, magnetic, and thermodynamic properties of the double perovskites Sr₂CrOsO₆ and Sr_1.5Ca₀.₅CrOsO₆. A strong Cr-O-Os super-exchange interaction and nearly full spin polarization (∼100 %) support the half-metallic behavior of Sr₂CrOsO₆, which has a gap of 0.951 eV in the majority spin channel and a high Curie temperature (T_C) of 724 K.</div><div>While maintaining metallic behavior in the minority channel, calcium doping causes a slight increase in the gap to approximately 1.162 eV and a reduction in spin polarization (∼50 %) in the majority channel. This shows a decrease in T_C at 520 K along with a continuation of the semi-metallic character, albeit somewhat diminished. The doped compound is a promising candidate for optoelectronic and thermoelectric applications, as evidenced by optical analysis that shows improved dielectric response, enhanced optical conductivity, and enhanced absorption (up to 54 cm⁻¹ at 3.6 eV). According to these findings, Sr₂CrOsO₆′s multifunctional properties can be efficiently tuned through targeted doping for high-temperature devices, especially those used in energy conversion and spintronics.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173441"},"PeriodicalIF":3.0,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903867","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":"Direct measurements of the adiabatic temperature change of rapidly quenched ribbon samples Ni50-xCoxMn50-yAly (x = 5, 6; y = 18, 19) in magnetic fields up to 8 T","authors":"Adler Gamzatov ,&nbsp;Anvar Kadirbardeev ,&nbsp;Yikyung Yu ,&nbsp;Nguyen Dan","doi":"10.1016/j.jmmm.2025.173453","DOIUrl":"10.1016/j.jmmm.2025.173453","url":null,"abstract":"<div><div>In this paper, we present the results of direct measurements of the adiabatic temperature change (ΔT_ad) in Ni₄₄Co₆Mn₃₂Al₁₈ and Ni₄₅Co₅Mn₃₁Al₁₉ ribbon samples in the temperature range of 100–350 K in a cyclic magnetic field of 1.8 T using the magnetic field modulation method, as well as in a magnetic field of 8 T using the classical extraction method. It is shown that near the magnetostructural phase transition (MSPT), the value of the inverse effect in a cyclic magnetic field of 1.8 T with a frequency of 0.2 Hz decreases significantly for both samples compared to the value of the effect with a single turn on of the magnetic field. For both samples, the behavior of ΔT_ad(H) near the MSPT in magnetic fields up to 8 T is irreversible. When the magnetic field is turned on, an inverse magnetocaloric effect (MCE) is observed with values of −1.8 K and −2.0 K at T = 250 and 264 K, respectively, for the Ni₄₄Co₆Mn₃₂Al₁₈ and Ni₄₅Co₅Mn₃₁Al₁₉ samples. Turning off the magnetic field leads to the irreversibility of the MCE for both samples, and the final temperature of the samples remains below the initial level. This is due to the fact that a magnetic field of 8 T is insufficient to induce MSPT in the entire volume of the sample, only part of the sample transitions from the martensite phase to the austenite phase. It is shown that by regulating the concentration of Co in Ni-Mn-Al alloys we can control the kinetics of the magnetostructural phase transition, which in the future will allow us to obtain alloys with specified characteristics for magnetic cooling technology.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173453"},"PeriodicalIF":3.0,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879653","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":"Ghost Dyakonov surface polariton in antiferromagnets","authors":"Qingxin Liu,&nbsp;Yubo Li,&nbsp;Song Bai,&nbsp;Xiangguang Wang,&nbsp;Haoyuan Song,&nbsp;Xuan-Zhang Wang","doi":"10.1016/j.jmmm.2025.173442","DOIUrl":"10.1016/j.jmmm.2025.173442","url":null,"abstract":"<div><div>We demonstrated that there is one new surface polariton in antiferromagnets with the easy axis lying in the surface plane in a normal external magnetic field. This polariton is a ghost Dyakonov surface polariton (GDSP) and is magnetically-tunable. It is produced by the external magnetic field from a Dyakonov surface magnon polariton, outside the AF reststrahlen band. Unlike the existing surface polaritons, its spin angular momentums (SAM) have three mutually normal components representing the orientation of GDSP polarization, and meanwhile its field, Poynting vector and SAM are of oscillation-attenuation with the penetration depth. The Goos-Hänchen shift-spectra of numerically-stimulated attenuated total reflection can more accurately reflect the GDSP existence. In addition, the choice of incident-beam polarization is very critical for the observation.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173442"},"PeriodicalIF":3.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893563","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":"Structural and magnetic behavior of milled EUROFER with Nb2O5 additions","authors":"Roberta Araujo Cavalcante de Menezes ,&nbsp;Diêgo Pires Gurgel ,&nbsp;Isaac Barros Tavares da Silva ,&nbsp;Ingryd Kely Cosme Melo ,&nbsp;Maria José Santos Lima ,&nbsp;Marcello Filgueira ,&nbsp;Marco Antonio Morales Torres ,&nbsp;José Humberto Araujo ,&nbsp;Uilame Umbelino Gomes","doi":"10.1016/j.jmmm.2025.173445","DOIUrl":"10.1016/j.jmmm.2025.173445","url":null,"abstract":"<div><div>EUROFER is a ferritic-martensitic steel with reduced activation, it is being used in the construction of nuclear fusion reactors due to its robust mechanical performance when exposed to radiation, neutron and helium bombardment. However, its operational temperature is limited to 500 °C, caused by microstructural changes at higher temperatures. This study investigates the structural and magnetic behavior of EUROFER alloy with the addition of niobium pentoxide (Nb₂O₅) after 15 h high-energy milling. The aim of this work is to study the microstructure, crystallite size, lattice parameters, and magnetic properties of the composite, using X-ray diffraction, magnetometry and Mössbauer spectroscopy. The results revealed significant reduction in crystallite size and alterations in magnetic properties, including decreased saturation magnetization and increased coercivity, while Mössbauer spectroscopy confirms no oxidation of EUROFER during the milling process and suggests Nb incorporation into the alloy. These findings suggested that the presence of Nb₂O₅ during the milling process promoted the formation of a new solid solution, making the alloy less susceptible to magnetic fields, an essential characteristic for applications involving exposure to high magnetic fields.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173445"},"PeriodicalIF":3.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885929","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":"Inequivalence of direct and converse nonlinear resonant magnetoelectric effects","authors":"D.A. Burdin ,&nbsp;D.V. Savelev ,&nbsp;N.A. Ekonomov ,&nbsp;V.I. Shishkin ,&nbsp;Y.K. Fetisov","doi":"10.1016/j.jmmm.2025.173444","DOIUrl":"10.1016/j.jmmm.2025.173444","url":null,"abstract":"<div><div>In this work, the inequivalence between the properties of nonlinear direct and converse magnetoelectric effects in a piezoelectric-ferromagnet composite structure consisting of a mechanically connected piezoelectric quartz plate and an yttrium iron garnet film on a gadolinium gallium garnet substrate is analyzed. Using the effective medium model, the dependence of the second voltage harmonic on the excitation field frequency is theoretically evaluated. A difference in the frequencies, at which the maximum response is observed, is caused by the sequence of acoustomagnetic and acoustoelectric transformations in the sample. For a theoretical description of the field dependences of the second harmonic, the Stoner-Wohlfarth model is used. It is shown that the dependence of the second voltage harmonic on the magnetic field for the converse effect can be qualitatively obtained by multiplying a similar dependence for the direct effect by the value of bias magnetic field. The results obtained are of interest to effectively develop devices based on magnetoelectric effect such as sensors and frequency doublers.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173444"},"PeriodicalIF":3.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889866","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":"Magnetocaloric stability of Mn4.8Cu0.2Ge3 in cyclic magnetic fields","authors":"Mani Barathi A ,&nbsp;Athul S R ,&nbsp;Fredrick Jean Paul J ,&nbsp;Anvar Kadirbardeev ,&nbsp;Swathi Sakthivel ,&nbsp;Adler Gamzatov ,&nbsp;Nagalakshmi Ramamoorthi","doi":"10.1016/j.jmmm.2025.173449","DOIUrl":"10.1016/j.jmmm.2025.173449","url":null,"abstract":"<div><div>A polycrystalline Mn_4.8Cu_0.2Ge₃ alloy with a hexagonal crystal structure and space group <em>P6₃/mcm</em> was synthesized using arc melting. The alloy undergoes a second-order transition from a ferromagnetic to a paramagnetic phase at <em>T_c</em>= 276.5 K. This sample is studied for its magnetocaloric effect (MCE) by direct measurements in a cyclic applied magnetic field, which is exactly a similar scenario of commercial refrigerators. The sample shows better magnetocaloric characteristics, and the properties are stable for long-term exposure of 15 min, corresponding to 190 cycles of an applied cyclic magnetic field of <em>ΔB</em> = 0–1.8 T. The MCE of the material has an unaccounted frequency dependence in which the value of adiabatic temperature change shows a 16 % drop over a frequency range of 1 Hz − 10 Hz. The magnetocaloric effect, also measured indirectly from heat capacity measurements for an applied magnetic field of <em>ΔB</em> = 0–1.8 T, shows a magnetic entropy change of 2.8 J/kg and adiabatic temperature change of 1.7 K, which are comparable with the direct measurement studies.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173449"},"PeriodicalIF":3.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867180","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":"Electrical resistivity and the magnetocaloric effect in Pr,TbAl2 compounds","authors":"Julio C.G. Tedesco ,&nbsp;Vagner Jandre ,&nbsp;Alexandre Magnus G. Carvalho ,&nbsp;Paula de Oliveira Ribeiro ,&nbsp;Bruno de Pinho Alho ,&nbsp;Pedro Jorge von Ranke ,&nbsp;Mario Reis ,&nbsp;Heloisa N. Bordallo","doi":"10.1016/j.jmmm.2025.173438","DOIUrl":"10.1016/j.jmmm.2025.173438","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This work presents a systematic investigation of the magnetic, thermodynamic, and electronic transport properties of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Pr&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;-&lt;/mo&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Tb&lt;/mi&gt;&lt;/mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/msub&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; pseudobinary compounds, with &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0.1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.2&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.25&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.3&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.4&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.5&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0.75&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, focusing on the similarities between the magnetocaloric effect and magnetoresistivity. To better understand their electrical resistivity and its behavior under an applied magnetic field, theoretical calculations of the isothermal entropy changes were carried out. This work extends the mean-field approach previously employed to iteratively and self-consistently calculate the eigenvalues and eigenvectors of the system’s Hamiltonian and to reproduce the experimental magnetic contribution to electrical resistivity data at zero applied magnetic field. In addition to providing new parameters that relate electron scattering to the magnetocaloric effect, a comparative and combined analysis of theoretical and experimental data for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; emphasizes similarities and differences as a function of temperature. While both &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; display similar shapes around and above the magnetic transition temperature, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, at lower temperatures, electron scattering and magnetic entropy appear to be differently influenced by the sublattices’ behavior, which depends on the temperature and the concentration &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. This offers a valuable contribution to the understanding of the phenomena exhibited by these materials. Consequently, from this study, a clear connection between technological applications, such as magnetic refrigeration, and some physical properties of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Pr&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;-&lt;/mo&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Tb&lt;/mi&gt;&lt;/mrow&gt;&lt;mi&gt;","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173438"},"PeriodicalIF":3.0,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the synergistic diffusion mechanism of double glow plasma alloying and its impact on the magnetic properties of non-oriented silicon steel","authors":"Xiaoyong Tao ,&nbsp;Zhehang Fan ,&nbsp;Qinghua Li ,&nbsp;Yiming Wen ,&nbsp;Zhiyuan Hu ,&nbsp;Gongtao Liu ,&nbsp;Aqib Mashood Khan ,&nbsp;Hongyan Wu","doi":"10.1016/j.jmmm.2025.173437","DOIUrl":"10.1016/j.jmmm.2025.173437","url":null,"abstract":"<div><div>This research investigates the element distribution, binding energy, and diffusion behavior of 3.5 wt% Si non-oriented electrical steel through carburization, nitridation, and carbonitridation processes, utilizing molecular dynamics simulation and double glow discharge surface alloying technology. Simulation results reveal a specific synergistic diffusion effect between carbon and nitrogen elements in the steel, with nitrogen playing a dominant role in promoting the diffusion depth of carbon in the steel. The double glow plasma surface alloying experiments demonstrate that as the carbon-to-nitrogen ratio increases, the carbon content rises and then declines, reaching its peak at a carbon-to-nitrogen ratio of 1:5, where both carbon and nitrogen contents achieve their maximum values. This phenomenon indicates that an appropriate carbon-to-nitrogen ratio effectively enhances the diffusion of both carbon and nitrogen elements in the matrix. In addition, nitriding significantly reduces the saturation magnetization of non-oriented electrical steels by approximately 20 %, with carbonitriding having the least effect on magnetic properties.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"630 ","pages":"Article 173437"},"PeriodicalIF":3.0,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893474","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}