38,174 results on '"ferromagnetic materials"'
Search Results
2. In-plane exchange field enhanced anomalous Andreev reflection in graphene-based ferromagnet/superconductor junctions.
- Author
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Tan, Chuan, Wu, Qingping, Li, Haoran, Liu, Zhengfang, and Xiao, Xianbo
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ANDREEV reflection , *SUPERCONDUCTORS , *SPINTRONICS , *FERROMAGNETIC materials , *GRAPHENE - Abstract
The study focused on investigating spin transport in a graphene-based ferromagnet/in-plane exchange field/superconductor junction. It was demonstrated that both the spin-flipped reflection and the anomalous Andreev reflection occur in the junction due to the spin-mixing effect induced by the in-plane exchange field in graphene. The research highlighted that increasing the Fermi energy in the junction can lead to a high level of anomalous Andreev reflection. Furthermore, the study also examined the charge conductance and spin-polarized conductance, showing that these properties are influenced by the strength of the vertical exchange field, the in-plane exchange field, and Fermi energy. The findings of this research could potentially open up new avenues for utilizing graphene in spintronics applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Anisotropic magnetic critical behavior of van der Waals room-temperature ferromagnet Fe5GeTe2 identified by magnetocaloric measurements.
- Author
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Liang, Rui, Zhou, Liang, Liu, Jiawei, and Tang, Nujiang
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MAGNETIC transitions , *CRITICAL exponents , *MAGNETIC anisotropy , *CURIE temperature , *MAGNETIC entropy , *FERROMAGNETIC materials - Abstract
Due to the room-temperature Curie temperature and large saturation moment, Fe5GeTe2 is considered a highly attractive van der Waals ferromagnet. Studying its magnetic critical behavior can provide valuable information about its magnetic phase transition. Notably, compared with the conventional methods for studying magnetic critical behavior, such as the modified Arrott plot, scaling analysis based on isothermal magnetic entropy change Δ S M (T , H) has advantages in dealing with the complex magnetic system Fe5GeTe2. However, studies on its magnetic critical behavior based on this method remain completely lacking. Here, we investigate the magnetic critical behavior of Fe5GeTe2 based on its Δ S M (T , H). Through scaling analysis of its Δ S M (T , H) , two sets of reliable critical exponents β, δ, and γ are obtained, which are 0.320(8), 7.99(1), and 2.24(2) for H//ab and 0.494(2), 4.28(4), and 1.62(3) for H//c. The significant difference between H//ab and H//c indicates strong anisotropy in its magnetic critical behavior. Furthermore, the fact that the obtained critical exponents for both H//ab and H//c cannot be simply described by a single universality class reveals a crossover of magnetic interactions in Fe5GeTe2. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Optimizing hybrid ferromagnetic metal–ferrimagnetic insulator spin-Hall nano-oscillators: A micromagnetic study.
- Author
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Xi, Robert, Lai, Ya-An, and Kent, Andrew D.
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PERPENDICULAR magnetic anisotropy , *FERROMAGNETIC materials , *SPIN excitations , *NANOELECTROMECHANICAL systems , *THIN films , *SPIN waves - Abstract
Spin-Hall nano-oscillators (SHNOs) are nanoscale spintronic devices that generate high-frequency (GHz) microwave signals useful for various applications, such as neuromorphic computing and creating Ising systems. Recent research demonstrated that hybrid SHNOs consisting of a ferromagnetic metal (permalloy) and lithium ferrite-based (LAFO) insulating ferrimagnetic thin films have advantages in having lower auto-oscillation threshold currents (I th) and generating larger microwave output power, making this hybrid structure an attractive candidate for spintronic applications. It is essential to understand how the tunable material properties of LAFO, e.g., its thickness, perpendicular magnetic anisotropy (K u , LAFO ), and saturation magnetization (M s , LAFO ), affect magnetic dynamics in hybrid SHNOs. We investigate the change in I th and the output power of the device as the LAFO parameters vary. We find the I th does not depend strongly on these parameters, but the output power has a highly nonlinear dependence on M s , LAFO and K u , LAFO . We further investigate the nature of the excited spin-wave modes as a function of K u , LAFO and determine a critical value of K u , LAFO above which propagating spin-waves are excited. Our simulation results provide a roadmap for designing hybrid SHNOs to achieve targeted spin excitation characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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5. Identifying the localized feature of 3d itinerant electrons of Fe in the van der Waals room-temperature ferromagnet Fe5GeTe2.
- Author
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Zhou, Liang, Liu, Jiawei, Liang, Rui, Li, Shuilin, Li, Ziying, and Tang, Nujiang
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CURIE temperature , *MAGNETIC anisotropy , *MAGNETIC properties , *OCEAN wave power , *FERROMAGNETIC materials - Abstract
The van der Waals itinerant ferromagnet Fe5GeTe2 has recently aroused great attention for the promising in spintronic devices applications. For such applications, the intrinsic magnetic properties such as magnetocrystalline anisotropy and room-temperature Curie temperature play the key role, both of which depend on the localized feature of its itinerant 3d electrons of Fe. Here, we study the localized feature of the itinerant 3d electrons of Fe of Fe5GeTe2. The results of Fe5GeTe2 single crystal show that the inverse susceptibility well fits the Curie–Weiss law above the paramagnetic Curie temperature TΔ ≈ 300 K, and the saturated magnetization follows a spin wave model with a power law of 1.525 below 30 K, both of which identify the strongly localized feature. Furthermore, the Rhodes–Wohlfarth ratio of approximately 2.4 of Fe5GeTe2 is higher than the value of 2.14 of vdW itinerant ferromagnet Fe3GeTe2, implying that the localized extent of the former is slightly lower than the latter. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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6. Identifying the localized feature of 3d itinerant electrons of Fe in the van der Waals room-temperature ferromagnet Fe5GeTe2.
- Author
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Zhou, Liang, Liu, Jiawei, Liang, Rui, Li, Shuilin, Li, Ziying, and Tang, Nujiang
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CURIE temperature ,MAGNETIC anisotropy ,MAGNETIC properties ,OCEAN wave power ,FERROMAGNETIC materials - Abstract
The van der Waals itinerant ferromagnet Fe
5 GeTe2 has recently aroused great attention for the promising in spintronic devices applications. For such applications, the intrinsic magnetic properties such as magnetocrystalline anisotropy and room-temperature Curie temperature play the key role, both of which depend on the localized feature of its itinerant 3d electrons of Fe. Here, we study the localized feature of the itinerant 3d electrons of Fe of Fe5 GeTe2 . The results of Fe5 GeTe2 single crystal show that the inverse susceptibility well fits the Curie–Weiss law above the paramagnetic Curie temperature TΔ ≈ 300 K, and the saturated magnetization follows a spin wave model with a power law of 1.525 below 30 K, both of which identify the strongly localized feature. Furthermore, the Rhodes–Wohlfarth ratio of approximately 2.4 of Fe5 GeTe2 is higher than the value of 2.14 of vdW itinerant ferromagnet Fe3 GeTe2 , implying that the localized extent of the former is slightly lower than the latter. [ABSTRACT FROM AUTHOR]- Published
- 2024
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7. Berry curvature induced anomalous Hall effect in Pt2MnGa.
- Author
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Kakati, Bhargab, Saha, Payal, Alom, Sadikul, and Sahariah, Munima B.
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ANOMALOUS Hall effect , *FERROMAGNETIC materials , *DENSITY functional theory , *POLAR effects (Chemistry) , *ELECTRONIC structure - Abstract
The intrinsic anomalous Hall effect in ferromagnetic materials depends on the spin–orbit-coupling-induced effect in the electronic structure. The presence of anomalous Hall effect can be realized from the existence of the finite Berry curvature. Since the Heusler material Pt2MnGa is ferromagnetic in its collinear state and no report on its transport properties has yet been made, the anomalous Hall effect in this system is investigated using a combined approach of the density functional theory and maximally localized Wannier function. Analysis of the Berry curvature reveals positive and negative peaks along the high symmetry k-points. These peaks together lead to a significant negative anomalous Hall conductivity, which makes the material a promising candidate for applications in spintronics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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8. Improvement of tunneling magnetoresistance induced by antiferromagnetic spin orientation.
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Chandrashekhar Koli, Shradha, Dupé, Bertrand, Zhou, Hangyu, and Zhao, Weisheng
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TUNNEL magnetoresistance , *MAGNETIC tunnelling , *MAGNETIZATION , *FERROMAGNETIC materials , *ANTIFERROMAGNETISM - Abstract
In magnetic tunnel junctions (MTJs), an antiferromagnetic iridium manganese (IrMn) layer neighboring a ferromagnetic electrode is indispensable for pinning the magnetization of the ferromagnet. The effect of its antiferromagnetism on adjacent ferromagnet and, thus, the quantum transport is, nevertheless, scarcely studied. Here, we investigate the role of antiferromagnetically orientated Mn spins in IrMn on the spin-dependent tunneling transport in IrMn/FeCo/MgO/FeCo/IrMn MTJ by analyzing the tunneling magnetoresistance (TMR) effect. The opposite spin orientation of Mn induces the mixing of Bloch symmetries, Δ 1 and Δ 5 , irrespective of the spin alignment of the FeCo electrode. This auxiliary contribution from the Mn spins improves the tunneling in majority- and minority-spin channels in parallel configuration. In the antiparallel configuration, the tunneling in majority- and minority-spin channels is non-identical. The TMR as high as 8643% is obtained under equilibrium. In addition, the non-equilibrium behavior of TMR and the spin-filtering effect are examined in the voltage bias range of 10–50 mV. The TMR ratio of 3600% with the spin-filtering efficiency of ∼ 98% is maintained at 50 mV, presenting the MTJ as an effective spin-filtering device robust to the bias endurance. Finally, it is speculated that our device structure can be a potential spin–orbit torque-based MTJ that offers a giant TMR and promotes upscaling of the generation of multi-bit devices with a simplified design strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Tunable intermediate states for neuromorphic computing with spintronic devices.
- Author
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Cheung, Shun Kong, Xiao, Zhihua, Liu, Jiacheng, Ren, Zheyu, and Shao, Qiming
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MAGNETIC fields , *SYSTEMS design , *HEAVY metals , *SPINTRONICS , *FERROMAGNETIC materials - Abstract
In the pursuit of advancing neuromorphic computing, our research presents a novel method for generating and precisely controlling intermediate states within heavy metal/ferromagnet systems. These states are engineered through the interplay of a strong in-plane magnetic field and an applied charge current. We provide a method for fine-tuning these states by introducing a small out-of-plane magnetic field, allowing for the modulation of the system's probabilistic response to varying current levels. We also demonstrate the implementation of a spiking neural network (SNN) with a tri-state spike timing-dependent plasticity (STDP) learning rule using our devices. Our research furthers the development of spintronics and informs neural system design. These intermediate states can serve as synaptic weights or neuronal activations, paving the way for multi-level neuromorphic computing architectures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Impact of dimensionality on the magnetocaloric effect in two-dimensional magnets.
- Author
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Patra, Lokanath, Quan, Yujie, and Liao, Bolin
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MAGNETOCALORIC effects , *MAGNETIC transitions , *MAGNETIC entropy , *ADIABATIC temperature , *MAGNETIC fields , *FERROMAGNETIC materials , *BIOMASS liquefaction - Abstract
Magnetocaloric materials, which exploit reversible temperature changes induced by magnetic field variations, are promising for advancing energy-efficient cooling technologies. The potential integration of two-dimensional materials into magnetocaloric systems represents an emerging opportunity to enhance the magnetocaloric cooling efficiency. In this study, we use atomistic spin dynamics simulations based on first-principles parameters to systematically evaluate how magnetocaloric properties transition from three-dimensional (3D) to two-dimensional (2D) ferromagnetic materials. We find that 2D features such as reduced Curie temperature, sharper magnetic transition, and higher magnetic susceptibility are beneficial for magnetocaloric applications, while the relatively higher lattice heat capacity in 2D can compromise achievable adiabatic temperature changes. We further propose GdSi 2 as a promising 2D magnetocaloric material. Our calculation predicts that GdSi 2 exhibits an isothermal entropy change Δ S M of 22.5 J kg − 1 K − 1 and an adiabatic temperature change Δ T a d of 6.2 K, near the hydrogen liquefaction temperature (T C ≈ 25 K). Our analysis offers valuable theoretical insights into the magnetocaloric effect in 2D ferromagnets and demonstrates that 2D ferromagnets hold promise for cooling and thermal management applications in compact and miniaturized nanodevices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
11. Optoelectronically controlled spin-valley filter and nonlocal switch based on an asymmetrical silicene magnetic superconducting heterostructure.
- Author
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Ma, Shuo, Zhang, Hongmei, Liu, Jianjun, and Liu, De
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ELECTRIC fields , *SUPERCONDUCTORS , *HANDEDNESS , *FERROMAGNETIC materials - Abstract
We investigate the effects of the circularly polarized light (CPL) and the electric field (EF) on the nonlocal transport in a silicene-based antiferromagnet/superconductor/ferromagnet (AF/S/F) asymmetrical junction. For case I (II), the CPL and the EF are applied simultaneously in the antiferromagnetic (ferromagnetic) region, whereas in the ferromagnetic (antiferromagnetic) region, only a constant EF is considered. The spin-valley-resolved conductance can be turned on or off by adjusting the CPL or the EF. The AF/S/F junction can be manipulated as a spin-locked valley filter for case I, while for case II, it can be used not only as a valley-locked spin filter but also as a nonlocal switch between two pure nonlocal processes. Such interesting nonlocal switch effect can be effectively controlled by reversing the direction of the incident energy axis, the handedness of the CPL, or the direction of the EF. These findings may open an avenue to the design and manufacture of the spintronic and valleytronic devices based on the asymmetrical silicene magnetic superconducting heterostructure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Far-field thermal radiation of layered ferromagnetic topological materials.
- Author
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Zhang, Yong-Mei and Wang, Jian-Sheng
- Subjects
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HEAT radiation & absorption , *FERROMAGNETIC materials , *GREEN'S functions , *TOPOLOGICAL insulators , *MAGNETIC films , *TOPOLOGICAL defects (Physics) - Abstract
High Chern number topological insulators can be obtained in a film of layered magnetic block system theoretically and experimentally. With nonzero Chern numbers, Chern insulators become valuable for fundamental topological physics and for improving next-generation electronic devices. We study energy and angular momentum radiation from layered topological insulators using the Dirac Fermion approach and by Green's function method. We make a connection between radiation magnitude and topological phase transitions. We find that the magnetic exchange field, intra-layer coupling, and inter-layer interaction are efficient measures to modify the energy radiation of layered topological materials. Moreover, the magnetic exchange field is indispensable for emitting angular momentum due to the need for breaking time-reversal symmetry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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13. Electric manipulation of the magnetization in heterostructure Pt/Co/Bi2Se3.
- Author
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Wang, Zhen, Wang, Fenglong, Shen, Hao, Hou, Zhaoyang, Wang, Jinguo, Shi, Gang, and Xu, Chunlong
- Subjects
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MAGNETIC control , *MAGNETIC torque , *MAGNETIZATION , *FERROMAGNETIC materials , *CRITICAL currents - Abstract
Spin–orbit torque (SOT) can provide efficient electrical manipulation of magnetism via applying electrical current to breaking the symmetry of damping-like torque. In the heterojunction of heavy and ferromagnetic metal, Dzyaloshinskii–Moriya interaction (DMI) is one of the key ingredients for stabilizing chiral spin structures, like chiral domain walls. Meanwhile, materials with larger charge-spin conversion rates are also highly expected for the efficient SOT. In this paper, spin–orbit torque magnetic switching is observed in the perpendicularly magnetized Pt/Co/Bi2Se3 and shows relatively high efficiency with low critical switching current density of about 5 × 105 A cm−2. The SOT efficiency and DMI in perpendicularly magnetized Pt/Co/Bi2Se3 were quantitatively investigated by electrical detection of the effective spin Hall field. The DMI constant is about 2.6 mJ m−2, and the effective spin Hall angle of Pt/Co/Bi2Se3 is about 0.14. The work also demonstrates that the Bi2Se3 layer takes the main responsibility for SOT, and the Pt/Co interface is the main source of DMI in Pt/Co/Bi2Se3 structures, which makes it possible to achieve independent optimization of DMI and SOT in the Pt/Co/Bi2Se3 structure at room temperature for the advanced application of spintronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Magnetic dynamics of strained non-collinear antiferromagnet.
- Author
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He, Zhiping and Liu, Luqiao
- Subjects
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SPIN waves , *SPIN excitations , *PERTURBATION theory , *FREQUENCIES of oscillating systems , *ANTIFERROMAGNETIC materials , *SUPERFLUIDITY , *FERROMAGNETIC materials - Abstract
In this work, we theoretically study the switching and oscillation dynamics in strained non-collinear antiferromagnet (AFM) Mn3X (X = Sn, Ge, etc.). Using the perturbation theory, we identify three separable dynamic modes—one uniform and two optical modes, for which we analytically derive the oscillation frequencies and effective damping. We also establish a compact, vector equation for describing the dynamics of the uniform mode, which is in analogy to the conventional Landau–Lifshitz–Gilbert (LLG) equation for ferromagnet but captures the unique features of the cluster octuple moment. Extending our model to include spatial inhomogeneity, we are able to describe the excitations of dissipative spin wave and spin superfluidity state in the non-collinear AFM. Furthermore, we carry out numerical simulations based on coupled LLG equations to verify the analytical results, where good agreements are reached. Our treatment with the perturbative approach provides a systematic tool for studying the dynamics of non-collinear AFM and is generalizable to other magnetic systems in which the Hamiltonian can be expressed in a hierarchy of energy scales. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Electric manipulation of the magnetization in heterostructure Pt/Co/Bi2Se3.
- Author
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Wang, Zhen, Wang, Fenglong, Shen, Hao, Hou, Zhaoyang, Wang, Jinguo, Shi, Gang, and Xu, Chunlong
- Subjects
MAGNETIC control ,MAGNETIC torque ,MAGNETIZATION ,FERROMAGNETIC materials ,CRITICAL currents - Abstract
Spin–orbit torque (SOT) can provide efficient electrical manipulation of magnetism via applying electrical current to breaking the symmetry of damping-like torque. In the heterojunction of heavy and ferromagnetic metal, Dzyaloshinskii–Moriya interaction (DMI) is one of the key ingredients for stabilizing chiral spin structures, like chiral domain walls. Meanwhile, materials with larger charge-spin conversion rates are also highly expected for the efficient SOT. In this paper, spin–orbit torque magnetic switching is observed in the perpendicularly magnetized Pt/Co/Bi
2 Se3 and shows relatively high efficiency with low critical switching current density of about 5 × 105 A cm−2 . The SOT efficiency and DMI in perpendicularly magnetized Pt/Co/Bi2 Se3 were quantitatively investigated by electrical detection of the effective spin Hall field. The DMI constant is about 2.6 mJ m−2 , and the effective spin Hall angle of Pt/Co/Bi2 Se3 is about 0.14. The work also demonstrates that the Bi2 Se3 layer takes the main responsibility for SOT, and the Pt/Co interface is the main source of DMI in Pt/Co/Bi2 Se3 structures, which makes it possible to achieve independent optimization of DMI and SOT in the Pt/Co/Bi2 Se3 structure at room temperature for the advanced application of spintronic devices. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
16. Oxidation tuning of ferroic transitions in Gd2C monolayer.
- Author
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Yang, Xinyu and Dong, Shuai
- Subjects
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TRANSITION metals , *SURFACE passivation , *SECOND harmonic generation , *METAL-insulator transitions , *KERR electro-optical effect , *FERROMAGNETIC materials - Abstract
Tuning of ferroic phases provides great opportunities for material functionalities, especially in two-dimensional materials. Here, a 4f rare-earth carbide Gd2C monolayer is predicted to be a ferromagnetic metal with large magnetization, inherited from its bulk property. Based on first-principles calculations, we propose a strategy that the surface passivation can effectively tune its ferroicity, namely, switching among ferromagnetic, antiferromagnetic, and ferroelectric phases. Metal–insulator transition also occurs accompanying these ferroic transitions. Our calculation also suggests that the magneto-optic Kerr effect and second harmonic generation are effective methods in monitoring these phase transitions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Polarization-selective optic-to-microwave conversion in a ferromagnetic insulator.
- Author
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Jeong, Taek, Kim, Dong Hwan, Kim, Dongkyu, Ihn, Yong Sup, Lee, Su-Yong, Jo, Yonggi, Kim, Jihwan, Kim, Zaeill, and Kim, Duk Y.
- Subjects
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MICROWAVE generation , *SPIN excitations , *VISIBLE spectra , *FERROMAGNETIC materials , *MICROWAVES , *PHOTONS - Abstract
Quantum technologies utilize photons in a wide range of spectra, from microwave to visible light. Interactions between photons at different frequencies can be mediated by the collective excitation of spins in a ferromagnetic material. Here, we present optic-to-microwave conversions using the spin mode. In the conversion system, we observe that the generation of microwaves can be controlled by the polarization of the infrared input. Furthermore, we miniaturize the system and demonstrate conversion in a cryogenic environment, where microwave photons can be manipulated in the quantum regime. We show that the conversion efficiency scales with the intensity of the infrared illumination. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Terahertz magnetic susceptibility of pyramid-shaped L10-FePt nanodot arrays.
- Author
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Zhao, Zhikun, Dai, Guohong, Wan, Shuhan, Yan, Weichao, Shen, Yun, Deng, Xiaohua, and Xing, Xiangjun
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MAGNETIC susceptibility , *MAGNETIC materials , *MAGNETIC anisotropy , *FERROMAGNETIC materials , *MAGNETIC devices , *NANODOTS - Abstract
Understanding the magnetic states and their dynamics in patterned ferromagnetic materials is of great importance for ultrahigh-density recording from the viewpoints of both fundamental research and practical applications. However, reliable access to magnetization dynamics in magnetic materials and devices on the technologically highly relevant terahertz range remains challenging. Currently, there is a lack of reports on terahertz magnetic susceptibility. Here, through micromagnetic simulations, we study the dynamics of pyramid-shaped, isolated magnetic nanodots and their arrays made of L10-FePt with high magnetocrystalline anisotropy. Numerical results reveal a significant magnetic response of isolated pyramid nanodots in the terahertz range. Specifically, two resonant modes, namely, a bulk mode and an edge mode, have been identified. For the lateral size above ∼100 nm, the nanodot's bulk mode splits and higher-order modes appear. Furthermore, the calculated spatial Fourier amplitude of resonant modes of nanopyramid arrays exhibits the dependence of lateral size and inter-dot spacing. These findings are expected to open up a promising route to terahertz spintronics utilizing magnetic nanostructures. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Critical behavior at ferromagnetic to paramagnetic phase transition in single crystalline MnNiSi ferromagnet.
- Author
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Zhang, Tingting, Gong, Yuanyuan, Lu, Ziqian, Bai, Yuqing, and Xu, Feng
- Subjects
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PHASE transitions , *FERROMAGNETIC materials , *CRITICAL exponents , *CURIE temperature , *MAGNETOCALORIC effects - Abstract
Ferromagnetic single crystalline MnNiSi samples were first fabricated through a Sn-flux growth technique, followed by measurements of their structural characteristics and intrinsic magnetic properties. Additionally, the critical behavior for second-order ferromagnetic to paramagnetic phase transition was investigated through utilization of techniques such as the modified Arrott plot, the Kouvel–Fisher method, and the magnetocaloric effect scaling law method. Through different methods of analysis, reliable critical exponents were obtained. Renormalization of interactions around the Curie temperature indicates the reliability of the obtained exponents. The obtained critical exponents are close to those theoretically predicted for a three-dimensional isotropic short-range Heisenberg ferromagnet but shift toward the long-range mean-field estimates. This may arise from the coupling of short- and long-range interactions as well as the competition between localized Mn–Mn magnetic interactions and the hybridization between p- and d-type orbitals. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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20. Space-time shape optimization of rotating electric machines.
- Author
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Cesarano, Alessio, Dapogny, Charles, and Gangl, Peter
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MAXWELL equations , *STRUCTURAL optimization , *ELECTRIC machines , *FERROMAGNETIC materials , *FINITE element method , *PERMANENT magnets - Abstract
This paper is devoted to the shape optimization of the internal structure of an electric motor, and more precisely of the arrangement of air and ferromagnetic material inside the rotor part with the aim to increase the torque of the machine. The governing physical problem is the time-dependent, nonlinear magneto-quasi-static version of Maxwell's equations. This multiphase problem can be reformulated on a 2D section of the real cylindrical 3D configuration; however, due to the rotation of the machine, the geometry of the various material phases at play (the ferromagnetic material, the permanent magnets, air, etc.) undergoes a prescribed motion over the considered time period. This original setting raises a number of issues. From the theoretical viewpoint, we prove the well-posedness of this unusual nonlinear evolution problem featuring a moving geometry. We then calculate the shape derivative of a performance criterion depending on the shape of the ferromagnetic phase via the corresponding magneto-quasi-static potential. Our numerical frameworkto address this problem is based on a shape gradient algorithm. The nonlinear time periodic evolution problems for the magneto-quasi-static potential is solved in the time domain, with a Newton–Raphson method. The discretization features a space-time finite element method, applied on a precise, meshed representation of the space-time region of interest, which encloses a body-fitted representation of the various material phases of the motor at all the considered stages of the time period. After appraising the efficiency of our numerical framework on an academic problem, we present a quite realistic example of optimal design of the ferromagnetic phase of the rotor of an electric machine. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. On the investigation of fractional coupled nonlinear integrable dynamical system: Dynamics of soliton solutions.
- Author
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Muhammad, Jan, Younas, Usman, Rezazadeh, Hadi, Hosseinzadeh, Mohammad Ali, and Salahshour, Soheil
- Subjects
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NONLINEAR dynamical systems , *OPTICAL solitons , *RICCATI equation , *NONLINEAR optics , *FERROMAGNETIC materials - Abstract
The primary focus of this paper is the investigation of the truncated M fractional Kuralay equation, which finds applicability in various domains such as engineering, nonlinear optics, ferromagnetic materials, signal processing, and optical fibers. As a result of its capacity to elucidate a vast array of complex physical phenomena and unveil more dynamic structures of localized wave solutions, the Kuralay equation has received considerable interest in the scientific community. To extract the solutions, the recently developed integration method, referred to as the modified generalized Riccati equation mapping (mGREM) approach, is utilized as the solving tool. Multiple types of optical solitons, including mixed, dark, singular, bright-dark, bright, complex, and combined solitons, are extracted. Furthermore, solutions that are periodic, hyperbolic, and exponential are produced. To acquire a valuable understanding of the solution dynamics, the research employs numerical simulations to examine and investigate the exact soliton solutions. Graphs in both two and three dimensions are presented. The graphical representations offer significant insights into the patterns of voltage propagation within the system. The aforementioned results make a valuable addition to the current body of knowledge and lay the groundwork for future inquiries in the domain of nonlinear sciences. The efficacy of the modified GREM method in generating a wide range of traveling wave solutions for the coupled Kuralay equation is illustrated in this study. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Ligand solid-solution tuning of magnetic and mechanical properties of the van der Waals metal–organic magnet NiCl2(btd)1−x(bod)x.
- Author
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Myatt, Emily, Lata, Simrun, Pitcairn, Jem, Daisenberger, Dominik, Kronawitter, Silva M., Hallweger, Sebastian A., Kieslich, Gregor, Argent, Stephen P., Tidey, Jeremiah P., and Cliffe, Matthew J.
- Subjects
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MAGNETIC properties , *LIGANDS (Chemistry) , *MAGNETISM , *FERROMAGNETIC materials , *COMPRESSIBILITY - Abstract
Van der Waals (vdW) magnets offer unique opportunities for exploring magnetism in the 2D limit. Metal–organic magnets (MOM) are of particular interest as the functionalisation of organic ligands can control their physical properties. Here, we demonstrate tuning of mechanical and magnetic function of a noncollinear vdW ferromagnet, NiCl2(btd) (btd = 2,1,3-benzothiadiazole), through creating solid-solutions with the oxygen-substituted analogue ligand 2,1,3-benzoxadiazole (bod). We synthesise NiCl2(btd)1−x(bod)x up to x = 0.33, above which we find mixtures primarily composed of 1D NiCl2(bod)2. Magnetometry reveals bod incorporation reduces the coercivity significantly (up to 60%), without altering the ordering temperatures. High pressure synchrotron diffraction measurements up to 0.4 GPa demonstrate that the stiffest axis is the b axis, through the Ni–N–(O/S)–N–Ni bonds, and the softest is the interlayer direction. Doping with bod fine-tunes this compressibility, softening the layers, but stiffening the interlayer axis. This demonstrates that substitution of organic ligands in vdW MOMs can be used to realise targeted magnetic and mechanical properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Ligand solid-solution tuning of magnetic and mechanical properties of the van der Waals metal–organic magnet NiCl2(btd)1−x(bod)x.
- Author
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Myatt, Emily, Lata, Simrun, Pitcairn, Jem, Daisenberger, Dominik, Kronawitter, Silva M., Hallweger, Sebastian A., Kieslich, Gregor, Argent, Stephen P., Tidey, Jeremiah P., and Cliffe, Matthew J.
- Subjects
MAGNETIC properties ,LIGANDS (Chemistry) ,MAGNETISM ,FERROMAGNETIC materials ,COMPRESSIBILITY - Abstract
Van der Waals (vdW) magnets offer unique opportunities for exploring magnetism in the 2D limit. Metal–organic magnets (MOM) are of particular interest as the functionalisation of organic ligands can control their physical properties. Here, we demonstrate tuning of mechanical and magnetic function of a noncollinear vdW ferromagnet, NiCl
2 (btd) (btd = 2,1,3-benzothiadiazole), through creating solid-solutions with the oxygen-substituted analogue ligand 2,1,3-benzoxadiazole (bod). We synthesise NiCl2 (btd)1−x (bod)x up to x = 0.33, above which we find mixtures primarily composed of 1D NiCl2 (bod)2 . Magnetometry reveals bod incorporation reduces the coercivity significantly (up to 60%), without altering the ordering temperatures. High pressure synchrotron diffraction measurements up to 0.4 GPa demonstrate that the stiffest axis is the b axis, through the Ni–N–(O/S)–N–Ni bonds, and the softest is the interlayer direction. Doping with bod fine-tunes this compressibility, softening the layers, but stiffening the interlayer axis. This demonstrates that substitution of organic ligands in vdW MOMs can be used to realise targeted magnetic and mechanical properties. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
24. Experimental investigation of low-frequency and pulsed eddy current testing in thickness measurement.
- Author
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Ge, Jiuhao, Xu, Fei, and Yusa, Noritaka
- Subjects
- *
EDDY current testing , *ALUMINUM alloys , *ALUMINUM plates , *ALLOY plating , *FERROMAGNETIC materials - Abstract
This paper experimentally compares low-frequency and pulsed eddy current testing techniques in measuring plate thickness. The experimental setups for both methods were built using general commercial devices. A single polarity rectangular wave with a 10 Hz pulse repetition frequency and 50% duty was utilised as the excitation wave in pulsed eddy current testing. Ferromagnetic steel and nonferromagnetic aluminium alloy plates of 1, 3, 5, and 10 mm thicknesses were tested at various lift-off distances. Using peak amplitude, valley amplitude, time to attenuate, logarithmic slope, and reciprocal square root of the logarithmic slope as features, pulsed eddy current testing could effectively evaluate the steel plates thicker than 3 mm and all the aluminium alloy plates. In contrast, low-frequency eddy current testing using a 10 Hz excitation frequency could evaluate both steel and aluminium alloy plates using signal phase. This indicates that redundant frequency components may impair the effectiveness of pulsed eddy current testing. Moreover, low signal-to-noise ratio and simple signal processing methods struggle to detect minor signal variations. Additionally, the linearity of phase versus thickness for steel is better than for aluminium alloy, potentially indicating that ferromagnetic materials enhance the coupling between the coil and the plate. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Electronic structures, magnetic properties, and high Curie temperature in a CrAs monolayer under strain.
- Author
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Feng, Yuan, Lu, Qiang, Fu, Wei, Ke, Sha-Sha, and Lü, Hai-Feng
- Subjects
- *
CURIE temperature , *DENSITY functional theory , *MONTE Carlo method , *MAGNETIC properties , *FERROMAGNETIC materials - Abstract
The exploration of two-dimensional (2D) intrinsic ferromagnetic materials has garnered significant attention in recent years. Most discovered 2D ferromagnets typically exhibit low Curie temperatures and unstable magnetic configurations under strain due to the competition between the direct exchange and the superexchange interaction. In this work, we apply the density functional theory to investigate the electronic structures, magnetic properties, and Curie temperatures of a single-atomic thick ferromagnet CrAs. Our findings indicate that the CrAs monolayer maintains half-metallic properties and a stable ferromagnetic state over a wide strain range of −10% to 10%. The Heisenberg exchange parameter J 1 can be regulated linearly from 28 to 51 meV. Furthermore, the Monte Carlo simulations demonstrate that the Curie temperature of the CrAs monolayer (942 K) is much higher than room temperature. These intriguing electronic and magnetic properties reveal that CrAs is a promising candidate for various spintronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Evidence for a Griffiths Phase to Cluster Spin Glass Transition in the La2/3Sr1/3(Mn1‐3xAl2xTix)O3 System.
- Author
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Lu, Ruie, Ji, Yuanchao, Wang, Yu, Ke, Xiaoqin, Tian, Fanghua, Zhou, Chao, Zhang, Yin, Liu, Chang, Yang, Sen, Ren, Xiaobing, and Song, Xiaoping
- Subjects
- *
SPIN crossover , *SPIN glasses , *GLASS transitions , *PHASE diagrams , *FERROMAGNETIC materials - Abstract
The presence of Griffiths phase to cluster spin glass transition has theoretically been predicted in both classical and quantum systems. However, its detection in a classical system has been lacking for decades, which hinders a complete understanding of the relationship between the Griffiths phase and cluster spin glass. Here, the experimental discovery of the Griffiths phase to cluster spin glass transition is reported in a classical magnetic system, diluted ferromagnets La2/3Sr1/3(Mn1‐3xAl2xTix)O3 (0 ≤ x ≤ 0.12). The phase diagram of the system shows a transition from the Griffiths phase into a ferromagnetic state in the low disorder concentration range (0.01 < x ≤ 0.09). In the high disorder concentration range (0.09 < x ≤ 0.12), a Griffiths phase to cluster spin glass transition is identified, which nicely matches that of disordered quantum systems. Moreover, the Griffiths phase is essentially an unfrozen cluster spin glass with partially broken ergodicity is demonstrated experimentally. These findings serve as crucial experimental references for understanding the glassy phenomena in disordered magnets, facilitating future exploration of their unique properties and functionalities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Influence of internal magnetic field on magnetization in ferromagnetic materials via Kraenkel–Manna–Merle system: dual-wave patterns, sensitivity and stability analysis: Influence of internal magnetic field on magnetization in ferromagnetic...: H. I. Abdel-Gawad et al
- Author
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Abdel-Gawad, H. I., Dossari, M. El, and EL-Gawaad, N. S. Abd
- Subjects
- *
MAGNETIC flux density , *MAGNETIC fields , *FERROMAGNETIC materials , *SOLITONS , *SENSITIVITY analysis - Abstract
In this study, it is shown that in the Kraenkel–Manna–Merle system (KMMS) an internal magnetic field (IMF) can be generated. This is achieved mathematically as the equation that describes the external magnetic field is integrable. An evolutionary system can generate an internal source by introducing the "duality transformation" which leads to creating "dual waves". Alongside a non-autonomous KMMS is considered, that describes nonuniform magnetic field formation. The system's exact solutions are found using the extended unified method. Various wave patterns are revealed, fission-fusion graded solitons, braided solitons, envelope solitons, zig-zag cliff wave shape, lump vector, zig-zag cavity solitons. and upper and lower saucers with surface-based lattices. The most revealed interesting phenomenon is the localization of the magnetic field created in FMMs, which agrees with the experimental work. The sensitivity of the system is tested against the IMF and also, against a perturbation in the external magnetic field. It is remarked that the intensity of the magnetic field, created in ferromagnetic materials, is highly exceeding that one of the external magnetic field amplitude. That is, magnetization by time varying magnetic field is highly efficient. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Design and Simulation of Conventional Rod Core Fluxgate Magnetometer and Analysis of Performance with Different Core Materials.
- Author
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Prakash, B. Gokul and Kollu, Pratap
- Subjects
- *
FLUXGATE magnetometers , *CORE materials , *MAGNETIC sensors , *FERROMAGNETIC materials , *METALLIC glasses - Abstract
A comprehensive analysis on conventional rod core fluxgate magnetometer has been done by designing multiple designs with varying number of turns of excitation coil (from hence will be referred to as EXC) and pick-up coil (PC) as well as different core diameter have in Ansys Maxwell and their electromagnetic simulations have been carried out, the results were analysed and are reported in this paper. Also, the current sweep analysis, frequency sweep analysis has been done to study the behaviour of the ferromagnetic core for different magnitudes of excitation current as well as for studying the variation in output induced voltage for different frequencies of the input excitation current. Finally, the electromagnetic simulation of 100 turns rod core design with different ferromagnetic core materials such as iron, ferrite, Metglas 2605 HB1M and Mu-metal has been done to study the sensor performance in terms of sensitivity. The results of all these conducted studies have been included in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. On the soliton-type and other physical solutions for the space–time fractional Kraenkel–Manna–Merle model.
- Author
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Alhejaili, Weaam, Shah, Rasool, Salas, Alvaro H, Raut, Santanu, Roy, Subrata, Roy, Ashim, and El-Tantawy, Samir A
- Subjects
- *
MATHEMATICAL physics , *FERROMAGNETIC materials , *SHOCK waves , *TRIGONOMETRIC functions , *NONLINEAR waves - Abstract
The space–time fractional Kraenkel–Manna–Merle system (FKMMS) is a mathematical physics system that is particularly established to outline the transmission of nonlinear short waves in ferromagnetic materials considering the impact of a zero conductivity external field. Motivated by this application, the current investigation seeks to thoroughly examine the space–time FKMMS with conformable fractional derivatives. Generalised EDAM (gEDAM), an improved variant of the modified extended direct algebraic method (EDAM), is utilised to efficiently find a collection of analytical travelling wave solutions in the form of rational, hyperbolic, exponential and trigonometric functions. Through a careful selection of particular values for the parameters associated with the arbitrary functions contained in the obtained solutions, the inferred solutions yield various new forms for travelling waves and other soliton-type structures. Within the scope of FKMMS, our analytical investigation identified many kink solitons, including kink, anti-kink, bell-shaped dark and brilliant kink. An analysis is conducted on the effects of several factors associated with the obtained solutions, including the space- and time-fractional parameters on the shock and solitary wave profiles. This work may provide critical new understandings for researchers, engineers and physicists working with ferromagnetic materials. Regarding the real-world occurrences seen throughout their experimental research, it can offer helpful insights. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Superconcentration for minimal surfaces in first passage percolation and disordered Ising ferromagnets.
- Author
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Dembin, Barbara and Garban, Christophe
- Subjects
- *
GROUND state energy , *COUPLING constants , *FERROMAGNETIC materials , *PERCOLATION , *CHIMNEYS , *MINIMAL surfaces - Abstract
We consider the standard first passage percolation model on Z d with a distribution G taking two values 0 < a < b . We study the maximal flow through the cylinder [ 0 , n ] d - 1 × [ 0 , h n ] between its top and bottom as well as its associated minimal surface(s). We prove that the variance of the maximal flow is superconcentrated, i.e. in O (n d - 1 log n) , for h ≥ h 0 (for a large enough constant h 0 = h 0 (a , b) ). Equivalently, we obtain that the ground state energy of a disordered Ising ferromagnet in a cylinder [ 0 , n ] d - 1 × [ 0 , h n ] is superconcentrated when opposite boundary conditions are applied at the top and bottom faces and for a large enough constant h ≥ h 0 (which depends on the law of the coupling constants). Our proof is inspired by the proof of Benjamini–Kalai–Schramm (Ann Probab 31:1970–1978, 2003). Yet, one major difficulty in this setting is to control the influence of the edges since the averaging trick used in Benjamini et al. (Ann Probab 31:1970–1978, 2003) fails for surfaces. Of independent interest, we prove that minimal surfaces (in the present discrete setting) cannot have long thin chimneys. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Investigation of Stress Concentration and Microdefect Identification in Ferromagnetic Materials within a Geomagnetic Field.
- Author
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Hu, Bo, Chong, Weilong, Shi, Wenze, and Qiu, Fasheng
- Subjects
- *
MARTENSITIC stainless steel , *BLIND source separation , *STRESS concentration , *FERROMAGNETIC materials , *GEOMAGNETISM - Abstract
Local damage or stress concentration that forms during manufacturing and long-term use of ferromagnetic materials has a direct impact on the safety of engineering structures. Thus, accurately identifying damage and stress conditions in these materials is crucial. In this study, martensitic stainless steel, a type of ferromagnetic material, is chosen as the subject for investigation. A weak magnetic detection device is engineered specifically for this purpose, and tests are conducted on the material using this device. The stress value of the material is determined using X-ray diffraction, while magnetic induction intensity is simultaneously recorded with a weak magnetic detection device along the same path. The stress value and magnetic induction intensity are normalized, and the results are analyzed to establish a correlation between weak magnetic signals and stress. Then, a signal processing technique combining blind source separation and eigenvalue recognition is introduced to achieve stress concentration and microdefect location identification. This method is based on the correlation analysis results between weak magnetic signals and stress, as well as supporting evidence from prior studies. The experimental results demonstrate that the location of stress concentration can be accurately determined by identifying the peak or valley value of weak magnetic signals, with an error range of less than 30%. The algorithm of blind source separation and eigenvalue recognition can pinpoint the location of stress concentration and microdefects from the obtained signal. This study presents a novel nondestructive testing method for stress concentration and microdefect identification in ferromagnetic materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Magnetic Properties of All- d Metallic Heusler Compounds: A First-Principles Study.
- Author
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Tas, Murat, Şaşıoğlu, Ersoy, and Galanakis, Iosif
- Abstract
All-d metallic Heusler compounds are promising materials for nanoelectronic applications. Such materials combining 3d, 4d, and 5d atoms have not yet been studied. In this respect, we perform ab initio electronic structure calculations and focus on Co 2 MnZ, Rh 2 MnZ, and Ru 2 MnZ compounds, where Z represents transition metal atoms from groups 3B, 4B, 5B, and 6B of the periodic table. Our results demonstrate that most of these compounds exhibit a distinctive region of very low minority-spin state density at the Fermi level when crystallized in the L 2 1 lattice structure. The Co-based compounds follow a Slater–Pauling behavior for their total spin magnetic moments, while the Ru-based compounds consistently deviate from the predicted Slater–Pauling values. Rh-based compounds show similarities to Co-based compounds for lighter Z atoms and to Ru-based compounds for heavier Z atoms. We find that the choice of the Z element within the same periodic table column has only a minor effect on the results, except for the Rh 2 Mn(Cr, Mo, W) compounds. Our findings suggest that these compounds hold significant promise for applications in spintronics and magnetoelectronics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Van der Waals magnetic materials for current-induced control toward spintronic applications.
- Author
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Ryu, Jeongchun, Kajale, Shivam Nitin, and Sarkar, Deblina
- Subjects
MAGNETIC materials ,MAGNETIC structure ,MAGNETIC properties ,ELECTRON spin ,FERROMAGNETIC materials - Abstract
Spintronics, leveraging electron spin for information processing, promises substantial advancements in energy-efficient computing. Van der Waals (vdW) magnetic materials, with their unique-layered structures and exceptional magnetic properties, have emerged as pivotal components in this field. This report explores the current-based control of vdW magnets, focusing on the spin–orbit torque (SOT) mechanism, which is crucial for spintronic applications. Key studies on Fe
3 GaTe2 /Pt and Fe3 GaTe2 /WTe2 heterostructures are highlighted, demonstrating efficient SOT switching at room temperature. The advantages of vdW magnets for SOT switching, including high spin-torque efficiencies and superior interface quality, are discussed. The report also examines future directions, such as wafer-scale growth techniques, materials design for enhanced Curie temperatures (Tc ), and the development of magneto tunnel junctions using all-vdW materials. These advancements underscore the potential of vdW magnetic materials in developing scalable, high-performance spintronic devices, paving the way for significant breakthroughs in energy-efficient computing. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
34. The Construction of Analytical Exact Soliton Waves of Kuralay Equation.
- Author
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Faridi, Waqas Ali, Bakar, Muhammad Abu, Myrzakulova, Zhaidary, Myrzakulov, Ratbay, Elamin, Mawahib, Ragoub, Lakhdar, and Akinyemi, Lanre
- Subjects
SOLITONS ,FERROMAGNETIC materials ,CAUCHY problem ,TRIGONOMETRY ,OPTICS - Abstract
The primary objective of this work is to examine the Kuralay equation, which is a complex integrable coupled system, in order to investigate the integrable motion of induced curves. The soliton solutions derived from the Kuralay equation are thought to be the supremacy study of numerous significant phenomena and extensive applications across a wide range of domains, including optical fibres, nonlinear optics and ferromagnetic materials. The inverse scattering transform is unable to resolve the Cauchy problem for this equation, so the analytical method is used to produce exact travelling wave solutions. The modified auxiliary equation and Sardar sub-equation approaches are used to find solitary wave solutions. As a result, singular, mixed singular, periodic, mixed trigonometric, complex combo, trigonometric, mixed hyperbolic, plane and combined bright–dark soliton solution can be obtained. The derived solutions are graphically displayed in 2-D and 3-D glances to demonstrate how the fitting values of the system parameters can be used to predict the behavioural responses to pulse propagation. This study also provides a rich platform for further investigation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Manipulation of Magnonic Activity by Electric Currents in Ferromagnetic Nanocylinders.
- Author
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Li, Zhisheng, Yang, Mingming, Fan, Mingming, Zeng, Xiaoyan, and Yan, Ming
- Subjects
ELECTRIC currents ,OPTICS ,FERROMAGNETIC materials ,SPIN waves ,BIREFRINGENCE ,MAGNETIZATION - Abstract
Electric currents passing through ferromagnets can impact the magnetization dynamics via the so-called spin-transfer torque (STT) effect. In this paper, we present a theoretical study on the current influence on magnonic activity, a recently reported spin wave (SW) chiral effect in ferromagnetic nanotubes. By micromagnetic simulations, we show that an electric current can cause a significant change in the rotatory power of the SW modes propagating in a longitudinally magnetized nanotube. This result is well explained by using the Fresnel model in optics assuming a SW circular birefringence. An analytical method is developed to solve the first-order mode, yielding perfect agreements with the numerical results. Our results provide a new approach to manipulate the SW propagating properties in ferromagnetic nanocylinders. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Double-barrier magnetic tunnel junctions with enhanced tunnel magnetoresistance.
- Author
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Zheng, Xiaohong, Yang, Shili, Zheng, Zhifan, Liu, Chun-Sheng, Wang, Weiyang, and Zhang, Lei
- Subjects
- *
MAGNETIC tunnelling , *TUNNEL magnetoresistance , *ENHANCED magnetoresistance , *GREEN'S functions , *FERROMAGNETIC materials - Abstract
Tunnel magnetoresistance (TMR) ratio is a key parameter characterizing the performance of a magnetic tunnel junction (MTJ), and a large TMR ratio is essential for the practical application of it. Generally, the traditional solutions to increasing the TMR ratio are to choose different material combinations as the ferromagnetic (FM) leads and nonmagnetic tunnel barrier. In this work, we study an architecture of MTJs of "FM/barrier/FM/barrier/FM" with double barriers, in contrast to the traditional single barrier structure "FM/barrier/FM." We first analytically show that double barrier MTJ will generally have much higher TMR ratio than the single barrier MTJ and then substantiate it with the well-known example of "Fe/MgO/Fe" MTJ. Based on density functional calculations combined with nonequilibrium Green's function technique for quantum transport study, in the single barrier "Fe/MgO/Fe" MTJ, the TMR ratio is obtained as 122%, while in the double barrier "Fe/MgO/Fe/MgO/Fe" MTJ, it is greatly increased to 802%, suggesting that double barrier design can greatly enhance the TMR and can be taken into consideration in the design of MTJs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Quantum Sensing of Room‐Temperature Ferromagnetism in 2D Van der Waals Fe3GaTe2 Using Divacancy Spins in SiC.
- Author
-
Chen, Xia, Luo, Qin‐Yue, Guo, Pei‐Jie, Zhou, Hao‐Jie, Hu, Qi‐Cheng, Wu, Hong‐Peng, Shen, Xiao‐Wen, Cui, Ru‐Yue, Dong, Lei, Wei, Tian‐Xing, Xiao, Yu‐Hang, Li, Deren, Lei, Li, Zhang, Xi, Wang, Jun‐Feng, and Xiang, Gang
- Subjects
- *
MAGNETIC properties , *MAGNETIC fields , *CURIE temperature , *FERROMAGNETISM , *FERROMAGNETIC materials - Abstract
Room‐temperature (RT) 2D van der Waals (vdW) ferromagnets hold immense promise for next‐generation spintronic devices for information storage and processing. To achieve high‐density energy‐efficient spintronic devices, it is essential to understand the local magnetic properties of RT 2D vdW magnets. In this work, noninvasive in situ stray field detection is realized in vdW‐layered ferromagnet Fe3GaTe2 using divacancy spins quantum sensor in silicon carbide (SiC) at RT. The structural features and magnetic properties of the Fe3GaTe2 are characterized utilizing X‐ray diffraction, scanning tsransmission electron microscopy, Raman spectrum, magnetization, and magneto‐transport measurements. Further detailed analysis of temperature‐ and magnetic field‐dependent optically detected magnetic resonances of the PL6 divacancy near the Fe3GaTe2 reveal that, the Curie temperature (
T c) of Fe3GaTe2 is ∼360 K, and the magnetization increases with external magnetic fields. Additionally, spin relaxometry technology is employed to probe the magnetic fluctuations of Fe3GaTe2, revealing a peak in the spin relaxation rate around theT c. These experiments give insights into the intriguing local magnetic properties of 2D vdW RT ferromagnet Fe3GaTe2 and pave the way for the application of SiC quantum sensors in noninvasive in situ stray field detection of related 2D vdW magnets. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
38. Mechanism of magnetic phase transition in correlated magnetic metal: insight into itinerant ferromagnet Fe3−δGeTe2.
- Author
-
Xu, Yuanji, Wang, Yue-Chao, Jin, Xintao, Liu, Haifeng, Liu, Yu, Song, Haifeng, and Tian, Fuyang
- Subjects
- *
MAGNETIC transitions , *METALS at low temperatures , *FERROMAGNETIC materials , *FERMI level , *QUANTUM states - Abstract
Developing a comprehensive magnetic theory for correlated itinerant magnets poses challenges due to the difficulty in reconciling both local moments and itinerant electrons. In this work, we investigate the microscopic process of magnetic phase transition in ferromagnetic metal Fe3−δGeTe2. We find that Hund's coupling is crucial for establishing ferromagnetic order. During the ferromagnetic transition, we observe the formation of quasiparticle flat bands and an opposing tendency in spectral weight transfer, primarily between the lower and upper Hubbard bands, across the two spin channels. Moreover, our results indicate that one of the inequivalent Fe sites exhibits Mott physics, while the other Fe site exhibits Hund's physics, attributable to their distinct atomic environments. We suggest that ferromagnetic order reduces spin fluctuations and makes flat bands near the Fermi level more distinct. The hybridization between the distinctly flat bands and other itinerant bands offers a possible way to form heavy fermion behavior in ferromagnets. The complex interactions of competing orders drive correlated magnetic metals to a new frontier for discovering outstanding quantum states. Understanding magnetism in correlated itinerant systems has been an important yet challenging task due to the complex interplay among Hund, Mott, and Kondo physics. In this work, by using DFT + DMFT, the authors reveal the mechanism of the magnetic phase transition and the heavy-fermion behavior in low temperatures in a ferromagnetic metal, shedding light on the roles of the above three factors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Tunable Anomalous Hall Effect in a Kagomé Ferromagnetic Weyl Semimetal.
- Author
-
Pate, Samuel E., Wang, Bin, Zhang, Yang, Shen, Bing, Liu, Enke, Martin, Ivar, Jiang, J. Samuel, Zhou, Xiuquan, Chung, Duck Young, Kanatzidis, Mercouri G., Welp, Ulrich, Kwok, Wai‐Kwong, and Xiao, Zhi‐Li
- Subjects
- *
ANOMALOUS Hall effect , *MAGNETIC fields , *MAGNETIC control , *TOPOLOGICAL property , *FERROMAGNETIC materials - Abstract
Emerging from the intricate interplay of topology and magnetism, the giant anomalous Hall effect (AHE) is the most known topological property of the recently discovered kagomé ferromagnetic Weyl semimetal Co3Sn2S2 with the magnetic Co atoms arranged on a kagomé lattice. Here it is reported that the AHE in Co3Sn2S2 can be fine‐tuned by an applied magnetic field orientated within ≈2° of the kagomé plane, while beyond this regime, it stays unchanged. Particularly, it can vanish in magnetic fields parallel to the kagomé plane and even decrease in magnetic fields collinear with the spin direction. This tunable AHE can be attributed to local spin switching enabled by the geometrical frustration of the magnetic kagomé lattice, revealing that spins in a kagomé ferromagnet change their switching behavior as the magnetic field approaches the kagomé plane. These results also suggest a versatile way to tune the properties of a kagomé magnet. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Mechanism of magnetic phase transition in correlated magnetic metal: insight into itinerant ferromagnet Fe3−δGeTe2.
- Author
-
Xu, Yuanji, Wang, Yue-Chao, Jin, Xintao, Liu, Haifeng, Liu, Yu, Song, Haifeng, and Tian, Fuyang
- Subjects
MAGNETIC transitions ,METALS at low temperatures ,FERROMAGNETIC materials ,FERMI level ,QUANTUM states - Abstract
Developing a comprehensive magnetic theory for correlated itinerant magnets poses challenges due to the difficulty in reconciling both local moments and itinerant electrons. In this work, we investigate the microscopic process of magnetic phase transition in ferromagnetic metal Fe
3−δ GeTe2 . We find that Hund's coupling is crucial for establishing ferromagnetic order. During the ferromagnetic transition, we observe the formation of quasiparticle flat bands and an opposing tendency in spectral weight transfer, primarily between the lower and upper Hubbard bands, across the two spin channels. Moreover, our results indicate that one of the inequivalent Fe sites exhibits Mott physics, while the other Fe site exhibits Hund's physics, attributable to their distinct atomic environments. We suggest that ferromagnetic order reduces spin fluctuations and makes flat bands near the Fermi level more distinct. The hybridization between the distinctly flat bands and other itinerant bands offers a possible way to form heavy fermion behavior in ferromagnets. The complex interactions of competing orders drive correlated magnetic metals to a new frontier for discovering outstanding quantum states. Understanding magnetism in correlated itinerant systems has been an important yet challenging task due to the complex interplay among Hund, Mott, and Kondo physics. In this work, by using DFT + DMFT, the authors reveal the mechanism of the magnetic phase transition and the heavy-fermion behavior in low temperatures in a ferromagnetic metal, shedding light on the roles of the above three factors. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
41. Numerical Simulation of Electromagnetic Nondestructive Testing Technology for Elasto–Plastic Deformation of Ferromagnetic Materials Based on Magneto–Mechanical Coupling Effect.
- Author
-
Hu, Xiangyi, Wang, Xiaoqiang, Cai, Haichao, Yang, Xiaokang, Pan, Sanfei, Yang, Yafeng, Tan, Hao, and Zhang, Jianhua
- Subjects
- *
ELECTROMAGNETIC testing , *NONDESTRUCTIVE testing , *MATERIAL plasticity , *MAGNETIC flux , *FERROMAGNETIC materials - Abstract
A numerical tool for simulating the detection signals of electromagnetic nondestructive testing technology (ENDT) is of great significance for studying detection mechanisms and improving detection efficiency. However, the quantitative analysis methods for ENDT have not yet been sufficiently studied due to the absence of an effective constitutive model. This paper proposed a new magneto–mechanical model that can reflect the dependence of relative permeability on elasto–plastic deformation and proposed a finite element–infinite element coupling method that can replace the traditional finite element truncation boundary. The validity of the finite element–infinite element coupling method is verified by the experimental result of testing electromagnetic analysis methods using TEAM Problem 7. Then, the reliability and accuracy of the proposed model are verified by comparing the simulation results under elasto–plastic deformation with experimental results. This paper also investigates the effect of elasto–plastic deformation on the transient magnetic flux signal, a quantitative hyperbolic tangent model between Bzpp (peak–peak value of the normal component of magnetic flux signal) and elastic stress, and the exponential function relationship between Bzpp and plastic deformation is established. In addition, the difference and mechanism of a magnetic flux signal under elasto–plastic deformations are analyzed. The results reveal that the variation of the transient magnetic flux signal is mainly due to domain wall pinning, which is significantly affected by elasto–plastic deformation. The results of this paper are important for improving the accuracy of quantitative ENDT for elasto–plastic deformation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Fiber‐Integrated van der Waals Quantum Sensor with an Optimal Cavity Interface.
- Author
-
Moon, Jong Sung, Whitefield, Benjamin, Spencer, Lesley, Kianinia, Mehran, Hennessey, Madeline, Toth, Milos, Jeon, Woong Bae, Kim, Je‐Hyung, and Aharonovich, Igor
- Subjects
- *
ENGINEERS , *BRAGG gratings , *BORON nitride , *FERROMAGNETIC materials , *REMOTE sensing - Abstract
Integrating quantum materials with fiber optics adds advanced functionalities to a variety of applications, and introduces fiber‐based quantum devices such as remote sensors capable of probing multiple physical parameters. However, achieving optimal integration between quantum materials and fibers is challenging, particularly due to difficulties in fabrication of quantum elements with suitable dimensions and an efficient photonic interface to a commercial optical fiber. Here a new modality for a fiber‐integrated van der Waals quantum sensor is demonstrated. A hole‐based circular Bragg grating cavity from hexagonal boron nitride (hBN) is designed and fabricated, engineer optically active spin defects within the cavity, and integrate the cavity with an optical fiber using a deterministic pattern transfer technique. The fiber‐integrated hBN cavity enables efficient excitation and collection of optical signals from spin defects in hBN, thereby enabling all‐fiber integrated quantum sensors. Moreover, remote sensing of a ferromagnetic material and of arbitrary magnetic fields is demonstrated. All in all, the hybrid fiber‐based quantum sensing platform may pave the way to a new generation of robust, remote, multi‐functional quantum sensors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Bi3+ doped nanocrystalline Ni–Co–Zn spinel ferrites: Tuning of physical, electrical, dielectric and magnetic properties for advanced spintronics applications.
- Author
-
Rahman, Md Mahfuzur, Hasan, Nazmul, Tabassum, Sumaiya, Rashid, M. Harun-Or, Rashid, Md Harunur, and Arifuzzaman, Md
- Subjects
- *
FOURIER transform infrared spectroscopy , *MAGNETIC anisotropy , *MAGNETIC properties , *MAGNETIC moments , *FERROMAGNETIC materials , *SELF-propagating high-temperature synthesis , *DIFFRACTION patterns - Abstract
This study reports the synthesis and characterization of nanocrystalline Ni 0.5 Co 0.2 Zn 0.3 Bi x Fe 2-x O 4 (x = 0.00, 0.025, 0.050, 0.075, 0.100) ferrites synthesized via the sol-gel auto combustion method. The structural, morphological, electric, dielectric, and magnetic properties of Bi3+-doped Ni–Co–Zn spinel ferrites annealed at 700 °C and further sintered at 850 °C, have been investigated towards analyzing the effect of Bi3+ doping. X-ray diffraction (XRD) patterns and Fourier Transform Infrared Spectroscopy (FTIR) spectra have revealed the single-phase cubic-spinel structure of all inspected materials while retaining their high crystalline nature. Their average crystallite size and average grain size are found in the nanoscale range (48–74 nm) and (46–67 nm), respectively. The saturation magnetization (M s) and experimental magnetic moment (η exp) are found to decrease with increasing Bi3+ content. The samples sintered at 850 °C display higher AC resistivity, attributing to the reduction of electrons hopping through grains in the samples. The low coercivity values (23.68–87.71 Oe) are observed, classifying the investigated materials as soft ferromagnetic. The increased magnetic anisotropy (K) through Bi3+ doping indicates tunable stability in magnetic orientations, making them suitable for spintronics applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Observation of planar Hall effect in the topological insulator NaCd4As3.
- Author
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Yang, Haiyang, Zhou, Yonghui, Wang, Jing, Zhou, Ying, Han, Yuyan, Wang, Jialu, Li, Yuke, Zhang, Xuefeng, and Yang, Zhaorong
- Subjects
- *
ENHANCED magnetoresistance , *TOPOLOGICAL insulators , *HALL effect , *GEOMETRIC quantum phases , *FERROMAGNETIC materials - Abstract
The observation of the planar Hall effect (PHE) illuminates the spin textures and topological properties of materials, indicating potential applications in quantum computing and electronic devices. Here, we present a study on the planar Hall transport of topological insulator NaCd4As3 single crystals. When the magnetic field is rotated within the sample plane relative to the current direction, we observe remarkable planar Hall resistivity and giant planar anisotropic magnetoresistance (AMR), both consistent with the theoretical expression of the PHE. Further analysis reveals that the orbital magnetoresistance effect, unrelated to surface electrons from topological surface states or bulk electrons from nontrivial Berry phases, lays a dominant role in the PHE in NaCd4As3. Additionally, the AMR ratio reaches −43% at 3 K under 14 T and remains −9% at room temperature, markedly exceeding that of traditional ferromagnetic metals. These findings provide a platform for understanding the PHE mechanism in topological insulators and highlight the potential of NaCd4As3 for angle and magnetic field detection applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Transport chirality generated by a tunable tilt of Weyl nodes in a van der Waals topological magnet.
- Author
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Tamanna, Afrin N., Lakra, Ayesha, Ding, Xiaxin, Buzi, Entela, Park, Kyungwha, Sobczak, Kamil, Deng, Haiming, Sharma, Gargee, Tewari, Sumanta, and Krusin-Elbaum, Lia
- Subjects
ELECTRONIC band structure ,SYMMETRY breaking ,CURIE temperature ,CHIRALITY ,FERROMAGNETIC materials - Abstract
Chirality — a characteristic handedness that distinguishes 'left' from 'right'—is a fundamental property of quantum particles under broken symmetry intimately connected to their spins. Chiral fermions have been identified in Weyl semimetals through their unique electrodynamics arising from 'axial' charge imbalance between pairs of chiral Weyl nodes—the topologically protected 'relativistic' crossings of electronic bands. Chiral magnetotransport phenomena critically depend on the details of electronic band structure. However, the putative emergence of chiral electronic channels through shape altering of Weyl nodes is yet to be revealed. Here, we detect chirality-endowed linear conduction channels promoted by a tilt of Weyl bands in inversion-symmetric Weyl ferromagnet MnSb
2 Te4 . The tuning of Weyl nodes is controlled with ionic hydrogen, which heals the system's (Mn-Te) bond disorder and lowers the internode scattering. The reshaped Weyl states feature a doubled Curie temperature ≳50 K and a strong angular transport chirality synchronous with a rare field-antisymmetric longitudinal resistance—a low-field tunable 'chiral switch' that is rooted in the interplay of Berry curvature, chiral anomaly and a hydrogen-mediated form of Weyl nodes. The possibility of tuning the shape of the Weyl nodes in topological magnets could open an avenue towards engineering their electrical behaviour. Here, the authors report the tuning of Weyl nodes and associated magnetotransport in MnSb2 Te4 by diffusion-controlled ionic hydrogen insertion. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
46. Observation of planar Hall effect in the topological insulator NaCd4As3.
- Author
-
Yang, Haiyang, Zhou, Yonghui, Wang, Jing, Zhou, Ying, Han, Yuyan, Wang, Jialu, Li, Yuke, Zhang, Xuefeng, and Yang, Zhaorong
- Subjects
ENHANCED magnetoresistance ,TOPOLOGICAL insulators ,HALL effect ,GEOMETRIC quantum phases ,FERROMAGNETIC materials - Abstract
The observation of the planar Hall effect (PHE) illuminates the spin textures and topological properties of materials, indicating potential applications in quantum computing and electronic devices. Here, we present a study on the planar Hall transport of topological insulator NaCd
4 As3 single crystals. When the magnetic field is rotated within the sample plane relative to the current direction, we observe remarkable planar Hall resistivity and giant planar anisotropic magnetoresistance (AMR), both consistent with the theoretical expression of the PHE. Further analysis reveals that the orbital magnetoresistance effect, unrelated to surface electrons from topological surface states or bulk electrons from nontrivial Berry phases, lays a dominant role in the PHE in NaCd4 As3 . Additionally, the AMR ratio reaches −43% at 3 K under 14 T and remains −9% at room temperature, markedly exceeding that of traditional ferromagnetic metals. These findings provide a platform for understanding the PHE mechanism in topological insulators and highlight the potential of NaCd4 As3 for angle and magnetic field detection applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
47. From Magnetostatics to Topology: Antiferromagnetic Vortex States in NiO‐Fe Nanostructures.
- Author
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Ślęzak, Michał, Wagner, Tobias, Bharadwaj, Venkata Krishna, Gomonay, Olena, Kozioł‐Rachwał, Anna, Menteş, Tevfik Onur, Locatelli, Andrea, Zając, Marcin, Wilgocka‐Ślęzak, Dorota, Dróżdż, Piotr, and Ślęzak, Tomasz
- Subjects
EXCHANGE interactions (Magnetism) ,MAGNETIC anisotropy ,PHASE diagrams ,FERROMAGNETIC materials ,MAGNETOSTATICS ,SPHEROMAKS - Abstract
Magnetic vortices are topological spin structures frequently found in ferromagnets, yet novel to antiferromagnets. By combining experiment and theory, it is demonstrated that in a nanostructured antiferromagnetic‐ferromagnetic NiO(111)‐Fe(110) bilayer, a magnetic vortex is naturally stabilized by magnetostatic interactions in the ferromagnet and is imprinted onto the adjacent antiferromagnet via interface exchange coupling. Micromagnetic simulations are used to construct a corresponding phase diagram of the stability of the imprinted antiferromagnetic vortex state. The in‐depth analysis reveals that the interplay between interface exchange coupling and the antiferromagnet magnetic anisotropy plays a crucial role in locally reorienting the Néel vector out‐of‐plane in the prototypical in‐plane antiferromagnet NiO and thereby stabilizing the vortices in the antiferromagnet. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Exploring soliton solutions of coupled dispersionless equations with new insights into bifurcation, chaos, and sensitivity through advanced analytical techniques.
- Author
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Riaz, H. W. A. and Farooq, Aamir
- Subjects
- *
DYNAMICAL systems , *NONLINEAR differential equations , *PARTIAL differential equations , *NONLINEAR equations , *FERROMAGNETIC materials - Abstract
In this study, we explore the dynamics of coupled dispersionless equations using the Galilean transformation and planar dynamical systems theory. These nonlinear equations are pivotal in various physics and engineering domains, such as optical fibers and ferromagnetic materials. We analyze bifurcation and chaotic behavior, finding that slight variations in initial conditions minimally affect solution sensitivity, as confirmed by the Runge–Kutta method. Using the improved modified Sardar sub-equation and ( G ′ G , 1 G )-expansion methods, we derive exact solutions, including bright, kink, anti-kink, and dark solitons. These results demonstrate the effectiveness of the proposed methods for solving nonlinear partial differential equations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Superconducting coupling through inhomogeneous magnetization in Bi2Sr2Ca2Cu3Oy/La2/3Ca1/3MnO3 nanocomposite.
- Author
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Krivoruchko, V. N., Tarenkov, V. Yu., and Belogolovskii, M.
- Subjects
- *
COOPER pair , *MAGNETIC fields , *EXCITATION spectrum , *FERROMAGNETIC materials , *BILAYERS (Solid state physics) , *CUPRATES - Abstract
Propagation of spin-singlet Cooper pairs from a conventional superconductor into a ferromagnetic material over comparatively long distances was explained by the emergence at their interface of equal-spin triplet pairing that is no longer subject to pair-breaking mechanisms within magnetic counterparts. This phenomenon is produced by interfacial magnetic inhomogeneity and most spectacularly manifests itself in all-oxide heterostructures involving cuprates and manganites. In contrast to previous works, mostly devoted to bilayers of these materials, we are studying the long-penetration effect in random binary nanocomposites formed by half-metallic La2/3Ca1/3MnO3 nanoparticles and micro-sized particles of a d-wave superconductor Bi2Sr2Ca2Cu3Oy. With point-contact spectro-scopy, we revealed the presence of two superconducting gaps, namely the gap Δd in the cuprate granules partly suppressed due to the proximity effect and the proximity-induced gap in the spectrum of excitations of equal-spin triplet Cooper pairs. External magnetic fields, which tend to align the magnetizations at and near the interfaces, significantly suppressed the features of the superconducting origin including a symmetrical periodic structure at energies less than the energy Δd, while the conductivity in the normal state changes only slightly. Like related oxide bilayers, it enables control of the supercurrent transfer across hybrid nanocomposite super-spintronic devices by tuning the degree of magnetic inhomogeneity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Magnetism in two-dimensional CoX2 (X = S, Se, and Te), from monolayer to bulk layered structures.
- Author
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Kindra, Karan and Singh, Ranber
- Subjects
- *
TRANSITION metal chalcogenides , *DENSITY functional theory , *FERMI level , *MAGNETIC structure , *FERROMAGNETIC materials - Abstract
We investigate spin-polarized electronic structures of CoX2 (X = S, Se, and Te) monolayers using the density functional theory. We find that CoS2 and CoSe2 monolayers are metallic ferromagnetic materials, whereas CoTe2 monolayer is nonmagnetic metallic material. The 3D bulk layered crystalline structures of CoX2 (X = S, Se, and Te) are found to be nonmagnetic metals in our calculations. In addition to the major contributions due to the d orbitals of Co atoms, there is also contribution from the p orbitals of chalcogen X atoms to the electronic structure near the Fermi level of CoX2. We are optimistic for the experimental growth and uses of these monolayer structures for the 2D spintronic applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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