Pub Date : 2025-01-30DOI: 10.1016/j.jmmm.2025.172837
S.A. Safwan, Nagwa El Meshad, A.S. Asmaa, M.H. Hekmat
The effects of external magnetic field and temperature on the magnetization and magnetic susceptibility (χ) of a neutral donor impurity in a parabolic GaAs (gallium arsenide) quantum dot were theoretically investigated. The Hamiltonian of an electron confined in a parabolic cylindrical quantum dot (CQD) with a neutral donor impurity (D0) in a magnetic field at different temperatures was solved variationally using the effective mass approximation. Within this framework, we explored how the ground state, excited states, and binding energies of the donor impurity varied with the temperature and the magnetic field strength. These energy states were employed in determining the canonical partition function, which was then utilized to determine the magnetic susceptibility and magnetization. The results indicated that the magnetization of exhibited a diamagnetic phenomenon across all examined temperatures. Additionally, the computed results demonstrated that the magnetic field could alter the magnetic properties of the CQD medium by changing the sign of its magnetic susceptibility from diamagnetic (χ < 0) to paramagnetic (χ > 0).
{"title":"Magnetic field-Induced magnetization and magnetic susceptibility for neutral donor impurity in cylindrical quantum dot","authors":"S.A. Safwan, Nagwa El Meshad, A.S. Asmaa, M.H. Hekmat","doi":"10.1016/j.jmmm.2025.172837","DOIUrl":"10.1016/j.jmmm.2025.172837","url":null,"abstract":"<div><div>The effects of external magnetic field and temperature on the magnetization and magnetic susceptibility (χ) of a neutral donor impurity in a parabolic GaAs (gallium arsenide) quantum dot were theoretically investigated. The Hamiltonian of an electron confined in a parabolic cylindrical quantum dot (CQD) with a neutral donor impurity (D<sup>0</sup>) in a magnetic field at different temperatures was solved variationally using the effective mass approximation. Within this framework, we explored how the ground state, excited states, and binding energies of the donor impurity varied with the temperature and the magnetic field strength. These energy states were employed in determining the canonical partition function, which was then utilized to determine the magnetic susceptibility and magnetization. The results indicated that the magnetization of <span><math><mrow><mi>G</mi><mi>a</mi><mi>A</mi><mi>s</mi></mrow></math></span> exhibited a diamagnetic phenomenon across all examined temperatures. Additionally, the computed results demonstrated that the magnetic field could alter the magnetic properties of the CQD <span><math><mrow><mi>G</mi><mi>a</mi><mi>A</mi><mi>s</mi></mrow></math></span> medium by changing the sign of its magnetic susceptibility from diamagnetic (χ < 0) to paramagnetic (χ > 0).</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172837"},"PeriodicalIF":2.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143202012","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 : 2025-01-30DOI: 10.1016/j.jmmm.2025.172838
Lu Xiao , Fei Chen , Xianfei Yin , Aimin Li , Shuyou Wang , Haopeng Li
The squeeze strengthening effect can significantly enhance the yield stress of magnetorheological(MR) fluids. However, the existing classical dipole model cannot accurately describe the microstructure of MR fluids under the squeeze-shear composite mode, and the constitutive model of yield stress under the composite mode is lacking. In this paper, the classical dipole method, finite element method, and magnetic energy analysis are used to analyze the interaction between particles in the squeeze-shear composite mode, and a fusion dipole model is proposed. A mathematical model of the magnetic energy density of the particle chain under the combined magnetic field and squeeze was established by analyzing the characteristics of the particle chain. By analyzing the micro yield process of MR fluid, the yield stress of MR fluid in composite mode is calculated and verified by experiments. Then, the constitutive model of MR fluid in composite mode is established. The results show that the yield stress accuracy of MR fluid calculated based on the fusion dipole model is more than 94.1%.
{"title":"The constitutive model of magnetorheological fluid in the squeeze-shear composite mode","authors":"Lu Xiao , Fei Chen , Xianfei Yin , Aimin Li , Shuyou Wang , Haopeng Li","doi":"10.1016/j.jmmm.2025.172838","DOIUrl":"10.1016/j.jmmm.2025.172838","url":null,"abstract":"<div><div>The squeeze strengthening effect can significantly enhance the yield stress of magnetorheological(MR) fluids. However, the existing classical dipole model cannot accurately describe the microstructure of MR fluids under the squeeze-shear composite mode, and the constitutive model of yield stress under the composite mode is lacking. In this paper, the classical dipole method, finite element method, and magnetic energy analysis are used to analyze the interaction between particles in the squeeze-shear composite mode, and a fusion dipole model is proposed. A mathematical model of the magnetic energy density of the particle chain under the combined magnetic field and squeeze was established by analyzing the characteristics of the particle chain. By analyzing the micro yield process of MR fluid, the yield stress of MR fluid in composite mode is calculated and verified by experiments. Then, the constitutive model of MR fluid in composite mode is established. The results show that the yield stress accuracy of MR fluid calculated based on the fusion dipole model is more than 94.1%.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"617 ","pages":"Article 172838"},"PeriodicalIF":2.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348713","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 : 2025-01-29DOI: 10.1016/j.jmmm.2025.172842
Xintao Wei , Yuyang Qian , Chaobo Liu , Chaoqun Pei , Bosen Li , Jing Hu , Baoan Sun , Guozhi Chai , Haibo Ke , Daqiang Gao
The pursuit of high-resolution and low-noise giant magnetoimpedance (GMI) sensors is paramount for weak magnetic field detection, hinging closely related to the intrinsic magnetic properties, especially for GMI effect, of core amorphous alloy wires (AAWs). While the doping of rare-earth (RE) elements is known to significantly affect the soft magnetic characteristics of amorphous alloys, its impact on the modulation of the GMI effect remains under-explored. This study addresses this gap by developing high-performance, multi-element RE-doped (Gd, Sm and Y) Co68Fe4Si14.8B10Cr3-RE0.2 AAWs through advanced microalloying and modified glass-coating techniques, achieving the remarkable GMI effect of 1128 % in GMI ratio and pT-level magnetic noise of 61pT/ Hz0.5 @ 1 Hz. Systematic analysis reveals that the incorporation of Sm markedly enhances the thermal stability of AAWs, leading to a remarkable effect permeability of 22,472 in GMI ratio and 0.88 A/m in coercivity. Most notably, the GMI sensor based on Sm-doped AAWs exhibits extraordinarily pT-level magnetic noise This work demonstrates a successful strategy for enhancing GMI sensor capabilities through RE elements microalloying, establishing a foundation for next-generation sensors with unparalleled precision and operational efficiency.
{"title":"Rare-earth doped cobalt-based amorphous alloy wires with enhanced performance of GMI sensor","authors":"Xintao Wei , Yuyang Qian , Chaobo Liu , Chaoqun Pei , Bosen Li , Jing Hu , Baoan Sun , Guozhi Chai , Haibo Ke , Daqiang Gao","doi":"10.1016/j.jmmm.2025.172842","DOIUrl":"10.1016/j.jmmm.2025.172842","url":null,"abstract":"<div><div>The pursuit of high-resolution and low-noise giant magnetoimpedance (GMI) sensors is paramount for weak magnetic field detection, hinging closely related to the intrinsic magnetic properties, especially for GMI effect, of core amorphous alloy wires (AAWs). While the doping of rare-earth (RE) elements is known to significantly affect the soft magnetic characteristics of amorphous alloys, its impact on the modulation of the GMI effect remains under-explored. This study addresses this gap by developing high-performance, multi-element RE-doped (Gd, Sm and Y) Co<sub>68</sub>Fe<sub>4</sub>Si<sub>14.8</sub>B<sub>10</sub>Cr<sub>3</sub>-RE<sub>0.2</sub> AAWs through advanced microalloying and modified glass-coating techniques, achieving the remarkable GMI effect of 1128 % in GMI ratio and pT-level magnetic noise of 61pT/ Hz<sup>0.5</sup> @ 1 Hz. Systematic analysis reveals that the incorporation of Sm markedly enhances the thermal stability of AAWs, leading to a remarkable effect permeability of 22,472 in GMI ratio and 0.88 A/m in coercivity. Most notably, the GMI sensor based on Sm-doped AAWs exhibits extraordinarily pT-level magnetic noise This work demonstrates a successful strategy for enhancing GMI sensor capabilities through RE elements microalloying, establishing a foundation for next-generation sensors with unparalleled precision and operational efficiency.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172842"},"PeriodicalIF":2.5,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We deposited epitaxial thin films of typical ferromagnetic Fe-Co-Ni alloys with various compositions on MgO (001) single crystal substrate by sputtering and then systematically investigated their magnetic anisotropy and magnetic damping constant α. The results showed that the magneto-crystalline anisotropy constant K1 roughly reproduced the composition dependence of bulk single crystals, but the region with K1 > 0 extended further on the Ni-rich side compared to the bulk’s. Additionally, uniaxial magnetic anisotropy on the order of 103 erg/cc was manifested in all the films. Regarding α, larger values were observed on the Ni-rich alloys, with a tendency to decrease with the addition of Fe or Co. Furthermore, the compositional dependence of α was found to replicate the behavior predicted by the Kamberský model.
{"title":"Magnetic anisotropy and damping in epitaxial Fe-Co-Ni binary and ternary alloy thin films","authors":"Tomoya Ueno , Takafumi Nakano , Masakiyo Tsunoda , Shogo Yamashita , Takayuki Hojo , Mikihiko Oogane","doi":"10.1016/j.jmmm.2025.172841","DOIUrl":"10.1016/j.jmmm.2025.172841","url":null,"abstract":"<div><div>We deposited epitaxial thin films of typical ferromagnetic Fe-Co-Ni alloys with various compositions on MgO (001) single crystal substrate by sputtering and then systematically investigated their magnetic anisotropy and magnetic damping constant <em>α</em>. The results showed that the magneto-crystalline anisotropy constant <em>K</em><sub>1</sub> roughly reproduced the composition dependence of bulk single crystals, but the region with <em>K</em><sub>1</sub> > 0 extended further on the Ni-rich side compared to the bulk’s. Additionally, uniaxial magnetic anisotropy on the order of 10<sup>3</sup> erg/cc was manifested in all the films. Regarding <em>α</em>, larger values were observed on the Ni-rich alloys, with a tendency to decrease with the addition of Fe or Co. Furthermore, the compositional dependence of <em>α</em> was found to replicate the behavior predicted by the Kamberský model.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172841"},"PeriodicalIF":2.5,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-29DOI: 10.1016/j.jmmm.2025.172813
Fang Si , Caiyin You , Hangjian Wang , Qi Zhang , Junbo Wang
In this study, nanoscale composite magnets containing Nd20.7Pr4.3Co6.8Ga0.3FebalB8.3 and Sm0.5Pr0.5Co5 hard magnetic phases were hot-pressed (HP) and hot-deformed (HD) by spark plasma sintering (SPS) method. The effects of height reductions on the microstructure, magnetic properties and electrochemical corrosion mechanisms of the dual-main-phase magnets were investigated. Results indicate that the HD method enhances the orientation degrees of both Nd2Fe14B and Sm0.5Pr0.5Co5 phases, while only slightly increasing grain size. The HD dual-main-phase magnets exhibit excellent corrosion resistance and magnetic properties, which are attributed to the textured structure and the distribution of Nd-rich phases in the composite magnets. Compared to the HP magnet, when the height reduction of the HD magnet was increased to 50 %, the remanence and maximum magnetic energy product of the composite magnets increased from 6.8 kG and 17.1 MGOe to 7.7 kG and 19.8 MGOe, respectively. As the height reduction increases, the Nd-rich phases encapsulating the Nd2Fe14B grains become narrower and are extruded into triangular regions between the main phase grains, which results in a strong exchange coupling effect and reduced coercivity. However, the narrowing and extrusion of the Nd-rich phase reduces the number of active reaction channels in electrochemical corrosion experiments, thereby enhancing corrosion resistance.
{"title":"Magnetic properties and corrosion cesistance of anisotropic NdFeB/SmPrCo magnets hot-deformed with various height reductions","authors":"Fang Si , Caiyin You , Hangjian Wang , Qi Zhang , Junbo Wang","doi":"10.1016/j.jmmm.2025.172813","DOIUrl":"10.1016/j.jmmm.2025.172813","url":null,"abstract":"<div><div>In this study, nanoscale composite magnets containing Nd<sub>20.7</sub>Pr<sub>4.3</sub>Co<sub>6.8</sub>Ga<sub>0.3</sub>Fe<sub>bal</sub>B<sub>8.3</sub> and Sm<sub>0.5</sub>Pr<sub>0.5</sub>Co<sub>5</sub> hard magnetic phases were hot-pressed (HP) and hot-deformed (HD) by spark plasma sintering (SPS) method. The effects of height reductions on the microstructure, magnetic properties and electrochemical corrosion mechanisms of the dual-main-phase magnets were investigated. Results indicate that the HD method enhances the orientation degrees of both Nd<sub>2</sub>Fe<sub>14</sub>B and Sm<sub>0.5</sub>Pr<sub>0.5</sub>Co<sub>5</sub> phases, while only slightly increasing grain size. The HD dual-main-phase magnets exhibit excellent corrosion resistance and magnetic properties, which are attributed to the textured structure and the distribution of Nd-rich phases in the composite magnets. Compared to the HP magnet, when the height reduction of the HD magnet was increased to 50 %, the remanence and maximum magnetic energy product of the composite magnets increased from 6.8 kG and 17.1 MGOe to 7.7 kG and 19.8 MGOe, respectively. As the height reduction increases, the Nd-rich phases encapsulating the Nd<sub>2</sub>Fe<sub>14</sub>B grains become narrower and are extruded into triangular regions between the main phase grains, which results in a strong exchange coupling effect and reduced coercivity. However, the narrowing and extrusion of the Nd-rich phase reduces the number of active reaction channels in electrochemical corrosion experiments, thereby enhancing corrosion resistance.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"618 ","pages":"Article 172813"},"PeriodicalIF":2.5,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402783","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 : 2025-01-28DOI: 10.1016/j.jmmm.2025.172812
Gopika C.T. , Prajisha K.P. , Apoorva Kaul , Umesh P. Borole , Jakeer Khan , Bhagaban Behera , P. Chowdhury
This study uses an integrated on-chip magnetic flux concentrator to explore the sensitivity enhancement of synthetic antiferromagnetic spin Valve (SV-SAF) sensors. Theoretical simulation on MFC indicates that a high magnetic gain factor up to 50 can be achieved with a lower air gap of and thicker, high permeability MFC material. In this report, a laminated film of [Ta/NiFe] of thickness was sputter deposited to achieve high permeability and low coercivity films. The magnetic gain factor was estimated by measuring the properties of the transfer curve of a single GMR-SV resistor embedded in the air gap. The results show that the magnetic gain of 25 and 46 were achieved by using 40 and air gap respectively. Further studies on Wheatstone bridge configuration reveal that the sensitivity of the spin valve can be improved to 10.7 mV/V/G in an operating field range of 0.5 G. These sensors have potential applications in low-field detection for healthcare applications.
{"title":"Enhancement of spin valve GMR sensor’s sensitivity with [Ta/NiFe]n on-chip magnetic flux concentrator","authors":"Gopika C.T. , Prajisha K.P. , Apoorva Kaul , Umesh P. Borole , Jakeer Khan , Bhagaban Behera , P. Chowdhury","doi":"10.1016/j.jmmm.2025.172812","DOIUrl":"10.1016/j.jmmm.2025.172812","url":null,"abstract":"<div><div>This study uses an integrated on-chip magnetic flux concentrator to explore the sensitivity enhancement of synthetic antiferromagnetic spin Valve (SV-SAF) sensors. Theoretical simulation on MFC indicates that a high magnetic gain factor up to 50 can be achieved with a lower air gap of <span><math><mrow><mn>20</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and thicker, high permeability MFC material. In this report, a laminated film of [Ta/NiFe]<span><math><msub><mrow></mrow><mrow><mi>n</mi></mrow></msub></math></span> of thickness <span><math><mo>∼</mo></math></span> <span><math><mrow><mn>1</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> was sputter deposited to achieve high permeability and low coercivity films. The magnetic gain factor was estimated by measuring the properties of the transfer curve of a single GMR-SV resistor embedded in the air gap. The results show that the magnetic gain of 25 and 46 were achieved by using 40 and <span><math><mrow><mn>20</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> air gap respectively. Further studies on Wheatstone bridge configuration reveal that the sensitivity of the spin valve can be improved to 10.7 mV/V/G in an operating field range of <span><math><mo>±</mo></math></span> 0.5 G. These sensors have potential applications in low-field detection for healthcare applications.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172812"},"PeriodicalIF":2.5,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165390","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 : 2025-01-26DOI: 10.1016/j.jmmm.2025.172833
Guokai Xu , Shaoqiu Xiao , Yan Li , Yunliang Long
Acoustically actuated magnetoelectric (ME) antenna is a novel electrically small antenna (ESA) technology currently attracting significant attention. It is anticipated to break through the limitations of electromagnetic (EM) wavelength, leading to a reduction in antenna size by orders of magnitude. However, modeling and analyzing ME antennas is always challenging, especially when considering micromagnetics and magnetoelastic coupling (MEC). In this work, the cellular model of the ME magnon-polaron antenna is proposed for the first time. Coupling the elastic, spin, and electromagnetic (EM) waves enables the conversion from radio frequency (RF) voltage to magnetoelastic waves (MEWs) to EM radiation. Ferromagnetic resonance (FMR) enhances the antenna’s radiation efficiency, and the magnon-polaron splits the acoustic resonance frequency. The reconfiguration of the antenna’s resonance and polarization characteristics can be achieved through the adjustment of the bias magnetic field. The blind spots in the radiation efficiency spectrum arise from either the standing spin waves or the polarization orthogonality between the spin and elastic waves. The modeling and analysis technique helps improve the design and boost the radiation performance of magnon-polaron antennas.
{"title":"Modeling electromagnetic radiation induced by magnetoelastic waves in thickness shear mode","authors":"Guokai Xu , Shaoqiu Xiao , Yan Li , Yunliang Long","doi":"10.1016/j.jmmm.2025.172833","DOIUrl":"10.1016/j.jmmm.2025.172833","url":null,"abstract":"<div><div>Acoustically actuated magnetoelectric (ME) antenna is a novel electrically small antenna (ESA) technology currently attracting significant attention. It is anticipated to break through the limitations of electromagnetic (EM) wavelength, leading to a reduction in antenna size by orders of magnitude. However, modeling and analyzing ME antennas is always challenging, especially when considering micromagnetics and magnetoelastic coupling (MEC). In this work, the cellular model of the ME magnon-polaron antenna is proposed for the first time. Coupling the elastic, spin, and electromagnetic (EM) waves enables the conversion from radio frequency (RF) voltage to magnetoelastic waves (MEWs) to EM radiation. Ferromagnetic resonance (FMR) enhances the antenna’s radiation efficiency, and the magnon-polaron splits the acoustic resonance frequency. The reconfiguration of the antenna’s resonance and polarization characteristics can be achieved through the adjustment of the bias magnetic field. The blind spots in the radiation efficiency spectrum arise from either the standing spin waves or the polarization orthogonality between the spin and elastic waves. The modeling and analysis technique helps improve the design and boost the radiation performance of magnon-polaron antennas.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172833"},"PeriodicalIF":2.5,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164786","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 : 2025-01-26DOI: 10.1016/j.jmmm.2025.172829
A. Samih , E. Salmani , Hussein. Sabbah , R. El Fdil , Z. Fadil , Fohad Mabood Husain , Seong Cheol Kim , Chaitany Jayprakash Raorane
This paper investigates the structural, electronic, and magnetic properties of SnC doped with transition metals (TMs) such as V, Cr, Mn, and Fe. The LDA and LDA + U approximations were employed to study the electronic properties of TM-doped SnC. Our findings demonstrate half-metallic behavior and ferromagnetism in these systems. We also calculated the Curie temperature for various TM concentrations and confirmed the mechanical and thermal stability of TM-doped SnC. Moreover, we extend zero-temperature first-principles DFT calculations of TM-doped SnC to finite-temperature Monte Carlo simulations using the Heat Bath algorithm to determine the curie temperature of Sn0.90TM0.10C (TM = V, Cr, Mn).These results enhance our understanding of doped SnC and provide valuable insights into its potential applications in advanced spintronic devices and nanotechnologies.
{"title":"Investigating Half-Metallic behavior of doped tin-carbide Sn(1-x)TM(x)C with TM = V, Cr, Mn and Fe: LDA and LDA + U analysis","authors":"A. Samih , E. Salmani , Hussein. Sabbah , R. El Fdil , Z. Fadil , Fohad Mabood Husain , Seong Cheol Kim , Chaitany Jayprakash Raorane","doi":"10.1016/j.jmmm.2025.172829","DOIUrl":"10.1016/j.jmmm.2025.172829","url":null,"abstract":"<div><div>This paper investigates the structural, electronic, and magnetic properties of SnC doped with transition metals (TMs) such as V, Cr, Mn, and Fe. The LDA and LDA + U approximations were employed to study the electronic properties of TM-doped SnC. Our findings demonstrate half-metallic behavior and ferromagnetism in these systems. We also calculated the Curie temperature for various TM concentrations and confirmed the mechanical and thermal stability of TM-doped SnC. Moreover, we extend zero-temperature first-principles DFT calculations of TM-doped SnC to finite-temperature Monte Carlo simulations using the Heat Bath algorithm to determine the curie temperature of Sn<sub>0</sub>.<sub>90</sub>TM<sub>0</sub>.<sub>10</sub>C (TM = V, Cr, Mn).These results enhance our understanding of doped SnC and provide valuable insights into its potential applications in advanced spintronic devices and nanotechnologies.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172829"},"PeriodicalIF":2.5,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165391","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 : 2025-01-26DOI: 10.1016/j.jmmm.2025.172828
Xiao-Xue Yang , Huiting Li , Je-Ho Shim, Xue-Feng Zhang, Xiao-Ping Ma, Junyan Gao, Xing Ri Jin, Hong-Guang Piao
The dynamic control and phase stability of transverse domain walls (TDWs) in nanowires are pivotal for advancing spintronic technologies. This study uses micromagnetic simulations to investigate TDWs in asymmetric Tie-shaped permalloy nanowires (T-NWs). By exploiting the continuously varying width of T-NWs, we uncover the intricate mechanisms of TDW pinning and motion under applied magnetic fields. Our findings highlight stable pinning processes and identify critical instabilities that herald phase transitions to vortex domain walls (VDWs). We systematically analyze non-equilibrium energy dynamics, including exchange, anisotropy, and Zeeman energies, and we elucidate the energy dissipation pathways and their role in TDW stabilization. The results reveal that TDW phase stability is highly sensitive to geometric asymmetry, providing key insights for optimizing nanowire designs to enhance TDW control. These insights pave the way for more efficient spintronic devices, particularly in applications requiring high-speed domain wall manipulation and robust magnetic state retention.
{"title":"Dynamic pinning and phase stability of transverse domain walls in asymmetric tie-shaped nanowires for spintronic applications","authors":"Xiao-Xue Yang , Huiting Li , Je-Ho Shim, Xue-Feng Zhang, Xiao-Ping Ma, Junyan Gao, Xing Ri Jin, Hong-Guang Piao","doi":"10.1016/j.jmmm.2025.172828","DOIUrl":"10.1016/j.jmmm.2025.172828","url":null,"abstract":"<div><div>The dynamic control and phase stability of transverse domain walls (TDWs) in nanowires are pivotal for advancing spintronic technologies. This study uses micromagnetic simulations to investigate TDWs in asymmetric Tie-shaped permalloy nanowires (T-NWs). By exploiting the continuously varying width of T-NWs, we uncover the intricate mechanisms of TDW pinning and motion under applied magnetic fields. Our findings highlight stable pinning processes and identify critical instabilities that herald phase transitions to vortex domain walls (VDWs). We systematically analyze non-equilibrium energy dynamics, including exchange, anisotropy, and Zeeman energies, and we elucidate the energy dissipation pathways and their role in TDW stabilization. The results reveal that TDW phase stability is highly sensitive to geometric asymmetry, providing key insights for optimizing nanowire designs to enhance TDW control. These insights pave the way for more efficient spintronic devices, particularly in applications requiring high-speed domain wall manipulation and robust magnetic state retention.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"616 ","pages":"Article 172828"},"PeriodicalIF":2.5,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165400","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 : 2025-01-26DOI: 10.1016/j.jmmm.2025.172832
Ranbin Wang , Zhanfan Jin , Wenhui Guo , You Wu , Jili Jia , Yang Shao , Na Chen , Kefu Yao
The development of Fe-based glassy powders and low-loss soft magnetic composites (SMCs) is a major challenge for advancing high-frequency and miniaturized electronic devices. In the present work, highly spherical glassy powders from a new Fe75B7C7P7Si3Mo0.5Cr0.5 alloy with high glass-forming ability (GFA) have been successfully prepared by a gas–water combined atomization method. The effects of compaction pressure on the magnetic properties of the corresponding SMCs were elucidated. High compaction pressure could effectively increase the magnetic volume fraction of the SMCs, thereby enhancing the effective permeability (μe). Additionally, the reduced total core loss (Pcv) could be mainly attributed to the reduced hysteresis loss associated with the decreased coercivity. At the maximum compaction pressure of 2000 MPa, the SMC exhibits optimal comprehensive performance, with a stable μe of 31.0 up to 1 MHz, a DC-Bias performance of 75.2 % under a 100 Oe field, and a Pcv of 5819 kW/m3 (100 mT, 500 kHz). These results could expedite the development of new low-loss SMCs.
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