Pub Date : 2025-12-23DOI: 10.1016/j.jmmm.2025.173783
S. Zriouel , M. Amzaoued , M. Mabrouki
<div><div>Diluted magnetic semiconductors based on <span><math><mrow><mi>I</mi><mi>V</mi><mo>−</mo><mi>V</mi><mi>I</mi></mrow></math></span> compounds are promising candidates for spintronic devices, where achieving robust and controllable magnetic ordering is essential. To understand how different transition-metal dopants influence these properties, we investigated Pb<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>TM<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>Se (TM = Ti, V, Cr, Mo) for <span><math><mrow><mi>x</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>10</mn><mo>−</mo><mn>0</mn><mo>.</mo><mn>18</mn></mrow></math></span> using the KKR-CPA method. The electronic structure reveals that Cr<span><math><mo>−</mo></math></span> and Mo<span><math><mo>−</mo></math></span>doped PbSe exhibit fully occupied <span><math><msup><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> states, with <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span> located in the <span><math><msup><mrow><msub><mrow><mi>e</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> level, whereas Ti<span><math><mo>−</mo></math></span>doping places <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span> within the partially occupied <span><math><msup><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> band. For V, <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span> is located between the states <span><math><msup><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> and <span><math><msup><mrow><msub><mrow><mi>e</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span>. Therefore, Cr<span><math><mo>−</mo></math></span> and V<span><math><mo>−</mo></math></span>doped PbSe are half-metallic, while Ti<span><math><mo>−</mo></math></span> and Mo<span><math><mo>−</mo></math></span>doped systems remain metallic. For Cr<span><math><mo>−</mo></math></span>, Mo<span><math><mo>−</mo></math></span>, and Ti<span><math><mo>−</mo></math></span>doped PbSe, the ferromagnetic configuration is energetically favored with positive <span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span> across all concentrations; in contrast, V<span><math><mo>−</mo></math></span>doping yields negative <span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span> at all compositions, confirming an antiferromagnetic ground state. The local magnetic moments vary strongly with the dopant: Cr maintains a large high-spin moment of <span><math><mrow><mo>(</mo><mo>∼</mo><mn>3</mn><mo>.</mo><mn>78</mn><msub><mrow><mi>μ</mi></mrow><mrow><mi>B</mi></mrow></msub><mo>)</mo></mrow></m
{"title":"First-principles KKR-CPA study of the structural, electronic, and magnetic behavior of PbSe Doped with Cr, Mo, Ti, and V for spintronic applications","authors":"S. Zriouel , M. Amzaoued , M. Mabrouki","doi":"10.1016/j.jmmm.2025.173783","DOIUrl":"10.1016/j.jmmm.2025.173783","url":null,"abstract":"<div><div>Diluted magnetic semiconductors based on <span><math><mrow><mi>I</mi><mi>V</mi><mo>−</mo><mi>V</mi><mi>I</mi></mrow></math></span> compounds are promising candidates for spintronic devices, where achieving robust and controllable magnetic ordering is essential. To understand how different transition-metal dopants influence these properties, we investigated Pb<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>TM<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>Se (TM = Ti, V, Cr, Mo) for <span><math><mrow><mi>x</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>10</mn><mo>−</mo><mn>0</mn><mo>.</mo><mn>18</mn></mrow></math></span> using the KKR-CPA method. The electronic structure reveals that Cr<span><math><mo>−</mo></math></span> and Mo<span><math><mo>−</mo></math></span>doped PbSe exhibit fully occupied <span><math><msup><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> states, with <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span> located in the <span><math><msup><mrow><msub><mrow><mi>e</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> level, whereas Ti<span><math><mo>−</mo></math></span>doping places <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span> within the partially occupied <span><math><msup><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> band. For V, <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span> is located between the states <span><math><msup><mrow><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span> and <span><math><msup><mrow><msub><mrow><mi>e</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow><mrow><mi>↑</mi></mrow></msup></math></span>. Therefore, Cr<span><math><mo>−</mo></math></span> and V<span><math><mo>−</mo></math></span>doped PbSe are half-metallic, while Ti<span><math><mo>−</mo></math></span> and Mo<span><math><mo>−</mo></math></span>doped systems remain metallic. For Cr<span><math><mo>−</mo></math></span>, Mo<span><math><mo>−</mo></math></span>, and Ti<span><math><mo>−</mo></math></span>doped PbSe, the ferromagnetic configuration is energetically favored with positive <span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span> across all concentrations; in contrast, V<span><math><mo>−</mo></math></span>doping yields negative <span><math><mrow><mi>Δ</mi><mi>E</mi></mrow></math></span> at all compositions, confirming an antiferromagnetic ground state. The local magnetic moments vary strongly with the dopant: Cr maintains a large high-spin moment of <span><math><mrow><mo>(</mo><mo>∼</mo><mn>3</mn><mo>.</mo><mn>78</mn><msub><mrow><mi>μ</mi></mrow><mrow><mi>B</mi></mrow></msub><mo>)</mo></mrow></m","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"640 ","pages":"Article 173783"},"PeriodicalIF":3.0,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145852443","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 : 2025-12-22DOI: 10.1016/j.jmmm.2025.173753
Gabriel A. Oliveira , Winder A. Moura-Melo , Afranio R. Pereira , Fábio S. Nascimento
Bilayer rectangular artificial spin ices (BRASIs) with distinct aspect ratios, , are considered. Namely, we investigate how the underlying geometry modifies the interaction between two rectangular artificial spin ice layers separated by a height offset, , whenever compared to the square case. Actually, rectangular layers interact by means of a Buckingham-like potential, whereas in the square case, one has an algebraic (van der Walls-like) interaction. In addition, Moiré patterns for BRASIs are less definite than for the square bilayer. We also deal with their basic thermodynamics, showing the behavior of the specific heat as a function of temperature and for a number of height offsets.
{"title":"Energetics and thermodynamics of bilayer rectangular artificial spin ices","authors":"Gabriel A. Oliveira , Winder A. Moura-Melo , Afranio R. Pereira , Fábio S. Nascimento","doi":"10.1016/j.jmmm.2025.173753","DOIUrl":"10.1016/j.jmmm.2025.173753","url":null,"abstract":"<div><div>Bilayer rectangular artificial spin ices (BRASIs) with distinct aspect ratios, <span><math><mi>γ</mi></math></span>, are considered. Namely, we investigate how the underlying geometry modifies the interaction between two rectangular artificial spin ice layers separated by a height offset, <span><math><mi>h</mi></math></span>, whenever compared to the square case. Actually, rectangular layers interact by means of a Buckingham-like potential, whereas in the square case, one has an algebraic (van der Walls-like) interaction. In addition, Moiré patterns for BRASIs are less definite than for the square bilayer. We also deal with their basic thermodynamics, showing the behavior of the specific heat as a function of temperature and <span><math><mi>γ</mi></math></span> for a number of height offsets.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173753"},"PeriodicalIF":3.0,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838539","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 : 2025-12-20DOI: 10.1016/j.jmmm.2025.173781
P. Skokowski , M. Matczak , Ł. Frąckowiak , T. Bednarchuk , M. Kowacz , B. Anastaziak , K. Synoradzki
<div><div>We present the structural, magnetic, and magnetocaloric properties of thin films with compositions Tb<sub>31</sub>Co<sub>69</sub> and Dy<sub>31</sub>Co<sub>69</sub> (at%) deposited on naturally oxidized silicon Si (100) substrates. Samples with a thickness <span><math><mrow><mi>d</mi><mo>=</mo><mn>50</mn><mspace></mspace><mi>nm</mi></mrow></math></span> covered with a protective Au overlayer with a thickness <span><math><mrow><msub><mrow><mi>d</mi></mrow><mrow><mi>Au</mi></mrow></msub><mo>=</mo><mn>5</mn><mspace></mspace><mi>nm</mi></mrow></math></span> were produced using the pulsed laser deposition technique. X-ray diffraction analysis indicated the presence of crystallized Laves phases and amorphous phases in the prepared materials. Magnetization measurements as a function of temperature revealed ferrimagnetic behavior in both samples. We estimated the compensation temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> of the amorphous phase for Tb<sub>31</sub>Co<sub>69</sub> at 81.5 K and for Dy<sub>31</sub>Co<sub>69</sub> at 88.5 K, while we found the Curie temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C, Laves</mi></mrow></msub></math></span> of the crystallized Laves phases at 204.5 K and at 117 K, respectively. We investigated the magnetocaloric effect in a wide temperature range, covering <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> of amorphous phases and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C, Laves</mi></mrow></msub></math></span> of crystallized Laves phases. The analysis for the magnetic field change of <span><math><mrow><mi>Δ</mi><msub><mrow><mi>μ</mi></mrow><mrow><mn>0</mn></mrow></msub><mi>H</mi><mo>=</mo><mn>5</mn></mrow></math></span> T showed values of the magnetic entropy change of <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>4</mn><mo>.</mo><mn>9</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> and <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>6</mn><mo>.</mo><mn>6</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C, Laves</mi></mrow></msub></math></span> for Tb<sub>31</sub>Co<sub>69</sub>, while for Dy<sub>31</sub>Co<sub>69</sub>, we determined the values of <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>35</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> and <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>28</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span>
{"title":"Magnetocaloric effect in Tb31Co69 and Dy31Co69 thin films deposited on Si substrates","authors":"P. Skokowski , M. Matczak , Ł. Frąckowiak , T. Bednarchuk , M. Kowacz , B. Anastaziak , K. Synoradzki","doi":"10.1016/j.jmmm.2025.173781","DOIUrl":"10.1016/j.jmmm.2025.173781","url":null,"abstract":"<div><div>We present the structural, magnetic, and magnetocaloric properties of thin films with compositions Tb<sub>31</sub>Co<sub>69</sub> and Dy<sub>31</sub>Co<sub>69</sub> (at%) deposited on naturally oxidized silicon Si (100) substrates. Samples with a thickness <span><math><mrow><mi>d</mi><mo>=</mo><mn>50</mn><mspace></mspace><mi>nm</mi></mrow></math></span> covered with a protective Au overlayer with a thickness <span><math><mrow><msub><mrow><mi>d</mi></mrow><mrow><mi>Au</mi></mrow></msub><mo>=</mo><mn>5</mn><mspace></mspace><mi>nm</mi></mrow></math></span> were produced using the pulsed laser deposition technique. X-ray diffraction analysis indicated the presence of crystallized Laves phases and amorphous phases in the prepared materials. Magnetization measurements as a function of temperature revealed ferrimagnetic behavior in both samples. We estimated the compensation temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> of the amorphous phase for Tb<sub>31</sub>Co<sub>69</sub> at 81.5 K and for Dy<sub>31</sub>Co<sub>69</sub> at 88.5 K, while we found the Curie temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C, Laves</mi></mrow></msub></math></span> of the crystallized Laves phases at 204.5 K and at 117 K, respectively. We investigated the magnetocaloric effect in a wide temperature range, covering <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> of amorphous phases and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C, Laves</mi></mrow></msub></math></span> of crystallized Laves phases. The analysis for the magnetic field change of <span><math><mrow><mi>Δ</mi><msub><mrow><mi>μ</mi></mrow><mrow><mn>0</mn></mrow></msub><mi>H</mi><mo>=</mo><mn>5</mn></mrow></math></span> T showed values of the magnetic entropy change of <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>4</mn><mo>.</mo><mn>9</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> and <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>6</mn><mo>.</mo><mn>6</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>C, Laves</mi></mrow></msub></math></span> for Tb<sub>31</sub>Co<sub>69</sub>, while for Dy<sub>31</sub>Co<sub>69</sub>, we determined the values of <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>35</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>comp</mi></mrow></msub></math></span> and <span><math><mrow><mo>−</mo><mi>Δ</mi><msub><mrow><mi>S</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mn>28</mn></mrow></math></span> mJ cm<sup>−3</sup> K<sup>−1</sup> at <span>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173781"},"PeriodicalIF":3.0,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838541","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}
The magnetic properties of Y1–xFexBa2Cu3Oy high-temperature superconducting samples with 0 ≤ x ≤ 0.05 in the normal (above the critical temperature T > Tc) and superconducting (at T < Tc) states have been studied. A major increase in the intragranular critical current density was previously observed for this system, reaching two orders of magnitude at the optimal Fe content xopt ∼ 0.04 near 77 K. The magnetic susceptibility has been measured at various temperatures in the region T > Tc. The contributions to the susceptibility from the Pauli paramagnetism of free carriers, from the magnetic moments of Fe ions, and from the BaCuO2 and CuO paramagnetic impurity phases present in the sample have been determined. The effective magnetic moment of Fe occupied Cu sites in the chain plane has been determined as μeff = 4.54μB. The middle lines of magnetic hysteresis loops in the superconducting state have been analyzed, and the paramagnetic contributions and the thermodynamic critical fields have been determined. It is concluded that the magnetic moments of Fe ions are completely preserved during the superconducting transition in the sample. This effect has been explained by the fact that nanoregions of the normal phase with dimensions of about the coherent length exist near magnetic substitutional defects.
{"title":"Magnetic properties of Fe-doped YBCO in the normal and superconducting states","authors":"K.S. Pigalskiy , N.N. Efimov , P.N. Vasilyev , A.A. Vishnev , L.I. Trakhtenberg","doi":"10.1016/j.jmmm.2025.173780","DOIUrl":"10.1016/j.jmmm.2025.173780","url":null,"abstract":"<div><div>The magnetic properties of Y<sub>1–<em>x</em></sub>Fe<sub><em>x</em></sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub><em>y</em></sub> high-temperature superconducting samples with 0 ≤ <em>x</em> ≤ 0.05 in the normal (above the critical temperature <em>T</em> > <em>T</em><sub>c</sub>) and superconducting (at <em>T</em> < <em>T</em><sub><strong><em>c</em></strong></sub>) states have been studied. A major increase in the intragranular critical current density was previously observed for this system, reaching two orders of magnitude at the optimal Fe content <em>x</em><sub>opt</sub> ∼ 0.04 near 77 K. The magnetic susceptibility has been measured at various temperatures in the region <em>T</em> > <em>T</em><sub>c</sub>. The contributions to the susceptibility from the Pauli paramagnetism of free carriers, from the magnetic moments of Fe ions, and from the BaCuO<sub>2</sub> and CuO paramagnetic impurity phases present in the sample have been determined. The effective magnetic moment of Fe occupied Cu sites in the chain plane has been determined as μ<sub>eff</sub> = 4.54μ<sub>B</sub>. The middle lines of magnetic hysteresis loops in the superconducting state have been analyzed, and the paramagnetic contributions and the thermodynamic critical fields have been determined. It is concluded that the magnetic moments of Fe ions are completely preserved during the superconducting transition in the sample. This effect has been explained by the fact that nanoregions of the normal phase with dimensions of about the coherent length exist near magnetic substitutional defects.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173780"},"PeriodicalIF":3.0,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838551","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}
To address the challenge of controlling cavitation-induced substrate damage during ultrasonic brazing, this study proposed a novel electromagnetic ultrasonic (EU) assisted brazing technique. The research explored the variation in sound pressure within the liquid solder Sn9Zn due to EU influence, as well as the mechanism and generation of cavitation effect. The results showed that the EU induced a sinusoidal periodic variation in sound pressure within the liquid solder, with the peak sound pressure showing a positive correlation to the peak current. Cavitation occurred when the sound pressure reached 0.226 MPa, with the maximum sound pressure recorded at 1.28 MPa. At 250 A peak current, the cavitation bubble exhibited rapid contraction, fragmenting into multiple small bubbles of unequal size and surface area. During collapse, the surrounding liquid pressure and flow velocity surged to 38.24 MPa and 44.13 m/s, respectively.
{"title":"Sound pressure and bubble collapse mechanisms in Sn9Zn liquid solder during electromagnetic ultrasonic assisted brazing","authors":"Mingxuan Zhang, Guoning Lu, Guijuan Chen, Qianqian Gao, Haonan Yu","doi":"10.1016/j.jmmm.2025.173767","DOIUrl":"10.1016/j.jmmm.2025.173767","url":null,"abstract":"<div><div>To address the challenge of controlling cavitation-induced substrate damage during ultrasonic brazing, this study proposed a novel electromagnetic ultrasonic (EU) assisted brazing technique. The research explored the variation in sound pressure within the liquid solder Sn<img>9Zn due to EU influence, as well as the mechanism and generation of cavitation effect. The results showed that the EU induced a sinusoidal periodic variation in sound pressure within the liquid solder, with the peak sound pressure showing a positive correlation to the peak current. Cavitation occurred when the sound pressure reached 0.226 MPa, with the maximum sound pressure recorded at 1.28 MPa. At 250 A peak current, the cavitation bubble exhibited rapid contraction, fragmenting into multiple small bubbles of unequal size and surface area. During collapse, the surrounding liquid pressure and flow velocity surged to 38.24 MPa and 44.13 m/s, respectively.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173767"},"PeriodicalIF":3.0,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799260","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 : 2025-12-17DOI: 10.1016/j.jmmm.2025.173745
P.L.S. Cambalame , B.J.C. Vieira , J.C. Waerenborgh , P.S.P. da Silva , J.A. Paixão
<div><div>We successfully synthesized a novel intermetallic compound <span><math><mrow><msub><mrow><mi>CrFe</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> with the <span><math><mrow><msub><mrow><mi>Fe</mi></mrow><mrow><mn>13</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>8</mn></mrow></msub></mrow></math></span>-type crystal structure. A structural study is presented combining single-crystal X-ray diffraction and Mössbauer spectroscopy analysis, confirming the presence of two distinct Fe sublattices. <span><math><mrow><msub><mrow><mi>CrFe</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> exhibits a metallic ferromagnetic state with <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub><mo>≈</mo><mn>200</mn><mspace></mspace><mi>K</mi></mrow></math></span>. This material does not follow the usual <span><math><mrow><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>∝</mo><mi>H</mi><mo>/</mo><mi>M</mi></mrow></math></span> Arrott law, rather a modified Arrott law is obeyed in this material. The critical exponents determined from detailed analysis of modified Arrott plots were found to be <span><math><mrow><mi>β</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>392</mn></mrow></math></span>, <span><math><mrow><mi>γ</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>309</mn></mrow></math></span> and <span><math><mrow><mi>δ</mi><mo>=</mo><mn>4</mn><mo>.</mo><mn>26</mn></mrow></math></span> obtained from the critical isotherm at <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub><mo>=</mo><mn>200</mn><mspace></mspace><mi>K</mi></mrow></math></span>. Self-consistency and reliability of the critical exponent analysis were verified by the Widom scaling law and scaling equations. Using the results from renormalization group calculation, the critical behavior of <span><math><mrow><msub><mrow><mi>CrFe</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> is akin to that of a <span><math><mrow><mi>d</mi><mo>=</mo><mn>3</mn><mo>,</mo><mi>n</mi><mo>=</mo><mn>3</mn></mrow></math></span> ferromagnet in which the magnetic exchange distance is found to decay as <span><math><mrow><mi>J</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo>≈</mo><msup><mrow><mi>r</mi></mrow><mrow><mo>−</mo><mn>4</mn><mo>.</mo><mn>86</mn></mrow></msup></mrow></math></span> with long-range magnetic coupling. The evaluated Rhodes–Wohlfarth ratio of <span><math><mrow><mo>∼</mo><mn>3</mn></mrow></math></span> points to an itinerant ferromagnetic ground state. Low-temperature measurements of resistivity, <span><math><mrow><mi>p</mi><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span>, and specific heat, <span><math><mrow><msub><mrow><mi>C</mi></mrow><mrow><mi>P</mi></mrow></msub><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow><
{"title":"CrFe2Ge2: Investigation of novel ferromagnetic material of Fe13Ge8-type crystal structure","authors":"P.L.S. Cambalame , B.J.C. Vieira , J.C. Waerenborgh , P.S.P. da Silva , J.A. Paixão","doi":"10.1016/j.jmmm.2025.173745","DOIUrl":"10.1016/j.jmmm.2025.173745","url":null,"abstract":"<div><div>We successfully synthesized a novel intermetallic compound <span><math><mrow><msub><mrow><mi>CrFe</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> with the <span><math><mrow><msub><mrow><mi>Fe</mi></mrow><mrow><mn>13</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>8</mn></mrow></msub></mrow></math></span>-type crystal structure. A structural study is presented combining single-crystal X-ray diffraction and Mössbauer spectroscopy analysis, confirming the presence of two distinct Fe sublattices. <span><math><mrow><msub><mrow><mi>CrFe</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> exhibits a metallic ferromagnetic state with <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub><mo>≈</mo><mn>200</mn><mspace></mspace><mi>K</mi></mrow></math></span>. This material does not follow the usual <span><math><mrow><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>∝</mo><mi>H</mi><mo>/</mo><mi>M</mi></mrow></math></span> Arrott law, rather a modified Arrott law is obeyed in this material. The critical exponents determined from detailed analysis of modified Arrott plots were found to be <span><math><mrow><mi>β</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>392</mn></mrow></math></span>, <span><math><mrow><mi>γ</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>309</mn></mrow></math></span> and <span><math><mrow><mi>δ</mi><mo>=</mo><mn>4</mn><mo>.</mo><mn>26</mn></mrow></math></span> obtained from the critical isotherm at <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>C</mi></mrow></msub><mo>=</mo><mn>200</mn><mspace></mspace><mi>K</mi></mrow></math></span>. Self-consistency and reliability of the critical exponent analysis were verified by the Widom scaling law and scaling equations. Using the results from renormalization group calculation, the critical behavior of <span><math><mrow><msub><mrow><mi>CrFe</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>Ge</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> is akin to that of a <span><math><mrow><mi>d</mi><mo>=</mo><mn>3</mn><mo>,</mo><mi>n</mi><mo>=</mo><mn>3</mn></mrow></math></span> ferromagnet in which the magnetic exchange distance is found to decay as <span><math><mrow><mi>J</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo>≈</mo><msup><mrow><mi>r</mi></mrow><mrow><mo>−</mo><mn>4</mn><mo>.</mo><mn>86</mn></mrow></msup></mrow></math></span> with long-range magnetic coupling. The evaluated Rhodes–Wohlfarth ratio of <span><math><mrow><mo>∼</mo><mn>3</mn></mrow></math></span> points to an itinerant ferromagnetic ground state. Low-temperature measurements of resistivity, <span><math><mrow><mi>p</mi><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span>, and specific heat, <span><math><mrow><msub><mrow><mi>C</mi></mrow><mrow><mi>P</mi></mrow></msub><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow><","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173745"},"PeriodicalIF":3.0,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799262","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 : 2025-12-17DOI: 10.1016/j.jmmm.2025.173779
Akanksha Namdeo , Yogesh Sharma , Mirza Tanweer Ahmad Beig
We present a theoretical and simulation study of one-dimensional (1D) magneto-photonic crystals (MPhCs) comprising alternating layers of Lithium Ferrite (LiFe-TT73) and Nickel Ferrite (NiFe-TT2). Using the transfer matrix method (TMM), we investigate Faraday rotation (FR), reflectance, transmittance, and the photonic band structure (PBS). The impact of magnetic field strength, number of periods, and layer thicknesses on the FR angle is systematically analysed. The structure exhibits negative effective permeability over specific frequencies, while maintaining a positive refractive index due to the ferrites' positive permittivity. Transmittance and reflectance strongly depend on structural parameters, particularly the number of periods and filling factor. The FR angle is found to be tunable with magnetic and structural variations, demonstrating dynamic control of nonreciprocal optical behaviour. Additionally, the PBS shows tunability under an external magnetic field, confirming magnetically induced nonreciprocity. These results highlight the potential of the 1D-MPhC design in tunable optical isolators, magneto optical devices, filters, and microwave photonic systems.
{"title":"Tunable Faraday rotation and photonic band engineering in 1D magneto-photonic crystals based on lithium and nickel ferrites","authors":"Akanksha Namdeo , Yogesh Sharma , Mirza Tanweer Ahmad Beig","doi":"10.1016/j.jmmm.2025.173779","DOIUrl":"10.1016/j.jmmm.2025.173779","url":null,"abstract":"<div><div>We present a theoretical and simulation study of one-dimensional (1D) magneto-photonic crystals (MPhCs) comprising alternating layers of Lithium Ferrite (LiFe-TT73) and Nickel Ferrite (NiFe-TT2). Using the transfer matrix method (TMM), we investigate Faraday rotation (FR), reflectance, transmittance, and the photonic band structure (PBS). The impact of magnetic field strength, number of periods, and layer thicknesses on the FR angle is systematically analysed. The structure exhibits negative effective permeability over specific frequencies, while maintaining a positive refractive index due to the ferrites' positive permittivity. Transmittance and reflectance strongly depend on structural parameters, particularly the number of periods and filling factor. The FR angle is found to be tunable with magnetic and structural variations, demonstrating dynamic control of nonreciprocal optical behaviour. Additionally, the PBS shows tunability under an external magnetic field, confirming magnetically induced nonreciprocity. These results highlight the potential of the 1D-MPhC design in tunable optical isolators, magneto optical devices, filters, and microwave photonic systems.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173779"},"PeriodicalIF":3.0,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838537","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 : 2025-12-16DOI: 10.1016/j.jmmm.2025.173764
Bijaya Kharel, Amrit Kumar Mondal, M. Benjamin Jungfleisch
We report the observation of two-dimensional (2D) random as well as one-dimensional (1D) string-like magnetization reversals in square artificial spin ice (ASI) induced by spin–orbit torque (SOT) in a bias magnetic field using micromagnetic simulations. A short pulse of SOT is applied in a single element of a strongly interacting square ASI array, leading to a magnetization switching of that element and triggering of magnetization reversal in nearby elements (i.e., “avalanche”), propagating in 2D when the preparation field is very close ( Oe) to the collective reversal field (avalanche field) and along a string-like chain when the preparation field is a few Oe away from that field. By analyzing the hysteresis loops and their corresponding field-driven avalanche fields, we study how the length and onset of the 1D string-like magnetization reversal are affected by the bias field. We find that the SOT-triggered 1D avalanche length can be tuned by varying the bias field strength, while the onset of the reversal is altered by the dipolar coupling strength. The results are explained by analyzing the stray field distribution, which shows that the polarity and strength of the stray field of the reversed island changes, facilitating the magnetization reversal in other islands in its vicinity. In addition, we calculated the total energy of the ASI system for each bias field, with various SOT-induced 1D string lengths, and observed local minima in the energy configuration limiting the 1D string length. Our results demonstrate the feasibility of an energy-efficient on-chip compatible approach for reconfiguring ASI necessary for next-generation magnonic reservoir computing.
{"title":"Spin–orbit torque-induced magnetization reversal in square artificial spin ice","authors":"Bijaya Kharel, Amrit Kumar Mondal, M. Benjamin Jungfleisch","doi":"10.1016/j.jmmm.2025.173764","DOIUrl":"10.1016/j.jmmm.2025.173764","url":null,"abstract":"<div><div>We report the observation of two-dimensional (2D) random as well as one-dimensional (1D) string-like magnetization reversals in square artificial spin ice (ASI) induced by spin–orbit torque (SOT) in a bias magnetic field using micromagnetic simulations. A short pulse of SOT is applied in a single element of a strongly interacting square ASI array, leading to a magnetization switching of that element and triggering of magnetization reversal in nearby elements (i.e., “avalanche”), propagating in 2D when the preparation field is very close (<span><math><mrow><mo>≈</mo><mn>1</mn></mrow></math></span> Oe) to the collective reversal field (avalanche field) and along a string-like chain when the preparation field is a few Oe away from that field. By analyzing the hysteresis loops and their corresponding field-driven avalanche fields, we study how the length and onset of the 1D string-like magnetization reversal are affected by the bias field. We find that the SOT-triggered 1D avalanche length can be tuned by varying the bias field strength, while the onset of the reversal is altered by the dipolar coupling strength. The results are explained by analyzing the stray field distribution, which shows that the polarity and strength of the stray field of the reversed island changes, facilitating the magnetization reversal in other islands in its vicinity. In addition, we calculated the total energy of the ASI system for each bias field, with various SOT-induced 1D string lengths, and observed local minima in the energy configuration limiting the 1D string length. Our results demonstrate the feasibility of an energy-efficient on-chip compatible approach for reconfiguring ASI necessary for next-generation magnonic reservoir computing.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173764"},"PeriodicalIF":3.0,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799258","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 : 2025-12-16DOI: 10.1016/j.jmmm.2025.173765
Hoang Van Thang, Nguyen Minh Quang, Nguyen Tien Tung, Le Thi Phuong Thanh, Dao Ngoc Hoanh, Trinh Nguyen Duy
A novel magnetic surface finishing process for single-crystal silicon materials has been proposed, demonstrating superior performance in both material removal capability and surface precision. The proposed method is based on the optimal combination of the magnetic field generated by a Halbach array and non-resonant vibration during processing. A strong magnetic field produced by the Halbach array with a magnitude of 537 mT not only improves the force acting on the abrasive particles but also improves polishing efficiency. The material removal model of the abrasive particles has been analyzed by considering and evaluating key influencing parameters including polishing gap, vibration frequency and amplitude, abrasive slurry flow rate, and polishing speed. Both the simulation and experimental results indicate that the material removal rate increases with higher vibration amplitude and frequency. In addition, reducing the polishing gap enhances the removal rate by up to 135.1 %, but simultaneously deteriorates the final workpiece surface quality due to the increased interaction forces. Moreover, conveyor speed and slurry flow rate are also key parameters that significantly affect both the material removal capability and the resulting surface quality. By simultaneously optimizing the influencing parameters through a combination of numerical simulation and experimental validation, the surface quality was substantially improved: after 60 min of finishing, the surface roughness Ra decreased from 529.61 nm to only 1.28 nm, while the material removal performance remained excellent, reaching 69.81 mg/h. These results not only confirm the outstanding effectiveness of the proposed method but also demonstrate its potential for widespread application in machining processes requiring high-precision surfaces.
{"title":"Simulation and experimental study of monocrystalline silicon surface polishing using a Halbach array combined with non-resonant vibration","authors":"Hoang Van Thang, Nguyen Minh Quang, Nguyen Tien Tung, Le Thi Phuong Thanh, Dao Ngoc Hoanh, Trinh Nguyen Duy","doi":"10.1016/j.jmmm.2025.173765","DOIUrl":"10.1016/j.jmmm.2025.173765","url":null,"abstract":"<div><div>A novel magnetic surface finishing process for single-crystal silicon materials has been proposed, demonstrating superior performance in both material removal capability and surface precision. The proposed method is based on the optimal combination of the magnetic field generated by a Halbach array and non-resonant vibration during processing. A strong magnetic field produced by the Halbach array with a magnitude of 537 mT not only improves the force acting on the abrasive particles but also improves polishing efficiency. The material removal model of the abrasive particles has been analyzed by considering and evaluating key influencing parameters including polishing gap, vibration frequency and amplitude, abrasive slurry flow rate, and polishing speed. Both the simulation and experimental results indicate that the material removal rate increases with higher vibration amplitude and frequency. In addition, reducing the polishing gap enhances the removal rate by up to 135.1 %, but simultaneously deteriorates the final workpiece surface quality due to the increased interaction forces. Moreover, conveyor speed and slurry flow rate are also key parameters that significantly affect both the material removal capability and the resulting surface quality. By simultaneously optimizing the influencing parameters through a combination of numerical simulation and experimental validation, the surface quality was substantially improved: after 60 min of finishing, the surface roughness Ra decreased from 529.61 nm to only 1.28 nm, while the material removal performance remained excellent, reaching 69.81 mg/h. These results not only confirm the outstanding effectiveness of the proposed method but also demonstrate its potential for widespread application in machining processes requiring high-precision surfaces.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173765"},"PeriodicalIF":3.0,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838536","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}
This study investigates the structural, dielectric, ferroelectric, magnetic, and magneto-dielectric properties of lead-free multiferroic composites (1-x) K0.5Na0.5NbO3-xBa0.7Sr0.3Fe12O19, where x = 0.10, 0.20, 0.30, 0.40, and 0.50, manufactured via a solid-state mixing route using individually pre-synthesized phases. Sol-gel auto-combustion was used to fabricate Ba0.7Sr0.3Fe12O19, whereas the solid-state reaction route was used to fabricate K0.5Na0.5NbO3. The K0.5Na0.5NbO3 and Ba0.7Sr0.3Fe12O19 were then mechanically mixed and sintered to create the multiferroic composite. X-ray diffraction with Rietveld refinement confirmed the presence of orthorhombic KNN and hexagonal BSFO phases free of secondary contaminants. FESEM scans revealed densely packed microstructures with polygonal KNN (1.66–3.80 μm) and hexagonal BSFO (0.75–1.17 μm) grains, resulting in high interfacial connection. Ferroelectric hysteresis loop analysis showed a remnant polarization (Pr) of 18.33 μC/cm2 and a coercive field (EC) of 24.71 kV/cm for x = 0.10 composition, showing robust ferroelectric behavior, while higher BSFO concentration generates increasingly leaky and lossy P-E loops. Magnetic studies showed that the x = 0.50 composition yielded the highest saturation magnetization of 29.68 emu/g. The x = 0.50 composition possesses the highest Curie temperature of ∼662 K, showing higher thermal stability. Magneto-dielectric measurements demonstrated a peak %MDC of 60.23 % for the x = 0.50 sample at 1.2 T and 100 Hz, correlating with high magnetization and interfacial polarization effects. Furthermore, the absence of a magnetoresistance effect, along with the dominance of Maxwell-Wagner interfacial polarization, confirms that the magneto-dielectric response is primarily driven by interfacial polarization rather than intrinsic transport mechanisms, making these composites appropriate for use in magnetically tunable capacitors, sensors, and multifunctional electronic devices.
{"title":"Enhanced magneto-dielectric coupling via Maxwell-Wagner polarization in lead-free K0.5Na0.5NbO3-Ba0.7Sr0.3Fe12O19 multiferroic composites","authors":"Arshdeep Kaur , Indu Sharma , Vishal Arora , Satvir Singh , Nitin Tandon , Harmanjit Singh Dosanjh , Nupur Prasad , Parambir Singh Malhi , Neeraj Bansal , Shaminder Singh , Chirag Garg , Anupinder Singh","doi":"10.1016/j.jmmm.2025.173766","DOIUrl":"10.1016/j.jmmm.2025.173766","url":null,"abstract":"<div><div>This study investigates the structural, dielectric, ferroelectric, magnetic, and magneto-dielectric properties of lead-free multiferroic composites (1-<em>x</em>) K0.5Na0.5NbO3-<em>x</em>Ba0.7Sr0.3Fe12O19, where <em>x</em> = 0.10, 0.20, 0.30, 0.40, and 0.50, manufactured via a solid-state mixing route using individually pre-synthesized phases. Sol-gel auto-combustion was used to fabricate Ba0.7Sr0.3Fe12O19, whereas the solid-state reaction route was used to fabricate K0.5Na0.5NbO3. The K0.5Na0.5NbO3 and Ba0.7Sr0.3Fe12O19 were then mechanically mixed and sintered to create the multiferroic composite. X-ray diffraction with Rietveld refinement confirmed the presence of orthorhombic KNN and hexagonal BSFO phases free of secondary contaminants. FESEM scans revealed densely packed microstructures with polygonal KNN (1.66–3.80 μm) and hexagonal BSFO (0.75–1.17 μm) grains, resulting in high interfacial connection. Ferroelectric hysteresis loop analysis showed a remnant polarization (Pr) of 18.33 μC/cm<sup>2</sup> and a coercive field (EC) of 24.71 kV/cm for <em>x</em> = 0.10 composition, showing robust ferroelectric behavior, while higher BSFO concentration generates increasingly leaky and lossy P-E loops. Magnetic studies showed that the <em>x</em> = 0.50 composition yielded the highest saturation magnetization of 29.68 emu/g. The <em>x</em> = 0.50 composition possesses the highest Curie temperature of ∼662 K, showing higher thermal stability. Magneto-dielectric measurements demonstrated a peak %MDC of 60.23 % for the <em>x</em> = 0.50 sample at 1.2 T and 100 Hz, correlating with high magnetization and interfacial polarization effects. Furthermore, the absence of a magnetoresistance effect, along with the dominance of Maxwell-Wagner interfacial polarization, confirms that the magneto-dielectric response is primarily driven by interfacial polarization rather than intrinsic transport mechanisms, making these composites appropriate for use in magnetically tunable capacitors, sensors, and multifunctional electronic devices.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"639 ","pages":"Article 173766"},"PeriodicalIF":3.0,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838540","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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