Accepted
, , Received Date: 2025-09-22
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In recent years, two-dimensional (2D) ferroelectric materials have attracted widespread interest due to their ultrathin geometry, high stability, and switchable polarization states. Ferroelectric tunnel junctions (FTJs) made from 2D ferroelectric materials exhibit exceptionally high tunnel electroresistance (TER) ratios, making them leading candidates for next-generation non-volatile memory and logic devices. However, advancing FTJ technology depends on overcoming the critical challenge of precisely controlling quantum tunneling resistance. Therefore, this study proposes a strategy of interfacial work function engineering, which actively modulates the band alignment of a heterostructure through ferroelectric polarization switching, induces a reversible metal-insulator transition in the barrier layer, and modulates TER. Using a van der Waals heterostructure composed of Al2Te3/In2Se3 as a model system, we demonstrate through first-principles calculations that the strategic manipulation of interfacial work functions can induce a reversible metal-insulator transition in the barrier, thereby drastically changing the tunneling conductance. Further analysis indicates that a work function mismatch between the two ferroelectric materials causes varying degrees of interfacial charge transfer, thereby triggering a metal-insulator transition in the van der Waals ferroelectric heterostructure as the external electric field is reversed. Non-equilibrium transport simulations reveal an unprecedented TER ratio of 2.69×105%. Our findings not only highlight Al2Te3/In2Se3 as a promising platform for high-performance FTJs but also establish a universal design strategy for engineering ultrahigh TER effects in low-dimensional ferroelectric memory devices. This work opens new avenues for developing energy-efficient, non-volatile memory with enhanced scalability and switching characteristics.
, , Received Date: 2025-09-21
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Tunneling Magnetoresistance (TMR) sensors have emerged as a leading technology in high-performance magnetic sensing, distinguished by their high sensitivity, low power consumption, and miniaturization. To address the evolving demands of cutting-edge applications like biomagnetic imaging and smart grid monitoring, continuous performance enhancement is crucial. This review systematically outlines the key strategies for optimizing TMR sensors, focusing on thin-film material engineering and sensitive microstructure design. Material advancements are dissected along two paths: developing high-sensitivity systems via MgO barriers and composite free layers, and creating wide-linear-range systems through anisotropy engineering, including both perpendicular (PMA) and in-plane (IMA) configurations, as well as dynamic methods like electric-field and strain modulation. Structurally, we highlight innovations such as vortex-state MTJs and magnetic flux concentrators to enhance linearity and sensitivity, alongside advanced noise modulation techniques that effectively suppress low-frequency 1/f noise. The practical impact of these optimizations is evidenced by TMR sensors now capable of measuring magnetocardiograms (MCG) outside shielded environments and providing high-accuracy current sensing in smart grids. Future development is directed towards novel material systems that balance high sensitivity with a wide linear range, the realization of monolithic three-axis vector sensors, and the deep integration of TMR technology with artificial intelligence for smart sensing systems. This work provides a comprehensive reference for advancing TMR sensor technology and its applications in high-precision magnetic field detection.
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Borohydrides (XBH4, X = Li, Na, K) exhibit an ”elemental synergy” effect, characterized by the high neutron absorption cross-section of boron and the excellent moderation capability of hydrogen, making them promising candidates for neutron shielding materials. However, the current lack of experimental and evaluated thermal scattering data for borohydrides in international nuclear data libraries hinders the accurate assessment of their shielding and moderation performance.In this study, material properties including lattice parameters, electronic structures, and phonon densities of states were calculated based on first-principles density functional theory. Subsequently, the corresponding S(α, β) data and thermal neutron scattering cross-sections were developed. The simulated lattice parameters show good agreement with experimental data. By comparing the electronic structures and phonon densities of states of XBH4, the coherent elastic, incoherent elastic, and inelastic scattering cross-sections for the cations X, B, and H were obtained. The results indicate that the thermal neutron cross-sections of the constituent nuclides in XBH4 exhibit significant differences depending on the cation X.To evaluate the impact of thermal scattering data on neutron shielding effects, a simplified fusion source model was employed using the OpenMC code to compare the leaked neutron energy spectra under different physical models. The results demonstrate that the Free Gas Model (FGM) provides an inaccurate description of neutron moderation due to its neglect of lattice binding effects. Furthermore, owing to the large incoherent scattering cross-section of hydrogen, the coherent elastic scattering cross-sections of the various nuclides have a negligible impact on the neutron energy spectrum. This research fills the gap in thermal neutron cross-section data for borohydrides and establishes a foundation for further investigations into their application as neutron shielding materials. These findings partially fill the gap in thermal neutron cross-section data for borohydrides and lay a foundation for their future application as neutron shielding materials.The datasets presented in this paper, including the ScienceDB, are openly available at https://www.doi.org/10.57760/sciencedb.j00213.00219(Please use the private access link https://www.scidb.cn/s/3meuq2).
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Based on the Gradient Boosting Decision Tree (GBDT) machine learning algorithm, this study develops a model for predicting the fusion reaction cross-section (CS) of 99-103Mo*, aiming to explore the optimal synthesis pathway for the medical isotope 99Mo. The model inputs include characteristic quantities such as reaction energy, proton number, mass number, and binding energy, as well as relevant parameters calculated based on phenomenological theoretical models, with the output being the fusion reaction cross-section. It is found that the mean absolute error (MAE) between the machine learning-predicted CS and experimental values on the test set is 0.0615, which is superior to the 0.1103 predicted by the EBD2 model. On this basis, combined with the GEMINI++ program, the survival probabilities of the neutron decay channels for 99-103Mo* were calculated to derive the evaporation residue cross-section of 99Mo. It is found that the evaporation residue cross-section of the 2n de-excitation channel for 4He+97Zr at a center-of-mass energy of 18.51 MeV is 1199.80 mb, making it the optimal pathway for synthesizing 99Mo. This research validates the reliability of physics-informed machine learning methods in predicting fusion reaction cross-sections and provides a reference for optimizing reaction system selection and producing medical isotopes through fusion reactions in heavy-ion accelerators.
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The interaction of nanosecond laser pulses with metallic materials involves multiple complex physical processes, and constructing a self-consistent model capable of uniformly describing all stages remains a significant challenge. This work establishes a multi-physics coupled model for pure iron, encompassing laser energy deposition, solid-liquid phase transition, gas-liquid interfacial kinetic transport, plasma expansion and ionization, and spectral radiation. The numerical solution employs a partitioned approach, utilizing an implicit compact difference scheme for the target region and a Mac-Cormack explicit scheme for the ambient atmosphere, to simulate the ablation dynamics.
The simulations elucidate the emergence of plasma shielding and its inhibitory effect on the evaporation process. They confirm that the early-stage ablation products are primarily transported via a supersonic expansion mode, which accounts for 81.6% of the total ablated mass transfer. The model successfully captures the complete evolution of the plasma plume from a high-temperature, highly ionized state (dominated by Fe3+) to a low-temperature, neutral atomic state (dominated by Fe0). Based on this, spectral calculations demonstrate the dynamic evolution of radiative characteristics from an early stage featuring a “strong continuum background dominated by ion lines” to a later stage where “the continuum attenuates, atomic lines become prominent, and self-absorption appears”. The emergence of self-absorption proves the model’s capability to effectively capture the optical thickness effects arising from spatial inhomogeneity within the plasma.
Through systematic comparison with experimentally measured spectra and calculated results from the PrismSPECT and NIST LIBS spectral programs, the model presented here achieved the highest comprehensive scores in quantitative evaluations across multiple channels. This validates the necessity and superiority of the full-chain self-consistent modeling approach over traditional methods relying on spatial averaging or the optically thin approximation, particularly in describing plasma inhomogeneity and radiation transport. It also provides a numerical simulation framework for applications such as laser processing parameter optimization, quantitative spectroscopic analysis, and the design of novel plasma light sources.
The simulations elucidate the emergence of plasma shielding and its inhibitory effect on the evaporation process. They confirm that the early-stage ablation products are primarily transported via a supersonic expansion mode, which accounts for 81.6% of the total ablated mass transfer. The model successfully captures the complete evolution of the plasma plume from a high-temperature, highly ionized state (dominated by Fe3+) to a low-temperature, neutral atomic state (dominated by Fe0). Based on this, spectral calculations demonstrate the dynamic evolution of radiative characteristics from an early stage featuring a “strong continuum background dominated by ion lines” to a later stage where “the continuum attenuates, atomic lines become prominent, and self-absorption appears”. The emergence of self-absorption proves the model’s capability to effectively capture the optical thickness effects arising from spatial inhomogeneity within the plasma.
Through systematic comparison with experimentally measured spectra and calculated results from the PrismSPECT and NIST LIBS spectral programs, the model presented here achieved the highest comprehensive scores in quantitative evaluations across multiple channels. This validates the necessity and superiority of the full-chain self-consistent modeling approach over traditional methods relying on spatial averaging or the optically thin approximation, particularly in describing plasma inhomogeneity and radiation transport. It also provides a numerical simulation framework for applications such as laser processing parameter optimization, quantitative spectroscopic analysis, and the design of novel plasma light sources.
, , Received Date: 2025-09-04
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, , Received Date: 2025-12-29
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Fusion reactions not only provide key information for studying the dynamic evolution and dissipation mechanisms in quantum many-body systems, but also open up an important avenue for exploring the reaction dynamics and structural characteristics of atomic nuclei. In recent years, with the continuous development of the technology for synthesizing new elements and their isotopes via fusion reactions, a series of new elements and their isotopes have been successfully synthesized. This paper systematically summarizes the synthesis pathways of elements in different mass regions, ranging from hydrogen to mendelevium, as well as the experimental progress of various heavy-ion fusion reactions from light systems to heavy systems. It reviews the advantages and limitations of current theoretical models in describing the capture process, and focuses on analyzing the strengths and shortcomings of phenomenological models and microscopic dynamic models in explaining the fusion behavior of different reaction systems. For the capture cross sections in light nuclei-light nuclei reaction systems, the EBD method, the CCFULL model, the universal Wong formula, and the ImQMD model all demonstrate good agreement with the experimental data. For the systems involving light nuclei-medium mass nuclei and light nuclei-heavy nuclei, the mentioned above models provide satisfactory descriptions. In particular, for the 16O+144Sm reaction system, the results obtained from the CCFULL model show good agreement with experimental data across both the sub-barrier and above-barrier energy regions. For the heavy nuclei-heavy nuclei systems, however, the EBD method holds a distinct advantage. Therefore, in subsequent predictions of the evaporation residue cross sections for superheavy elements, the results calculated by the EBD method can serve as the input for the capture cross section. On this basis, several key scientific issues in fusion reaction research are proposed, including heavy-ion fusion hindrance, the phenomenon of fusion suppression at extreme sub-barrier energies, fusion probability $P_{\text{CN}}$, and the fission barrier of compound nuclei, etc. Furthermore, an outlook and suggestions for future research directions in fusion reactions are provided.
, , Received Date: 2025-09-24
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, , Received Date: 2025-09-15
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The Back-n white neutron facility at the China Spallation Neutron Source (CSNS) provides neutrons in the 0.3 eV–300 MeV energy range, severing as a crucial platform for neutron-induced nuclear reaction studies in China. With a flight length of about 76 m, neutrons in Endstation 2 show excellent neutron energy resolution, providing nice conditions for experiments such as neutron capture cross-section measurements relevant to astrophysical nucleosynthesis and key nuclear data. Measurements of neutron capture reactions mainly employ low- to intermediate-energy neutrons (below 1 MeV), and the precision of experimental results strongly depends on the neutron energy spectrum in this energy range. Benefiting from the stable operation of the CSNS, the neutron energy spectrum of Back-n remains highly stable over extended periods, but it also evolves with structural adjustments of the CSNS’s components such as the target and beam window. In this work, the 6Li-Si beam monitor at Back-n Endstation 2 was used to measure the low- to intermediate-energy neutron spectrum under the 50-15-40 collimator configuration in different preiods. Relative neutron energy spectra in the 0.3 eV–1 MeV range (100 bpd) were obtained before and after the proton beam window replacement in 2024 and the target structure adjustment in 2025. The unfolding threshold was extended down to 10 eV, achieving total uncertainty of 1%–6.8%. The results indicate that the new proton beam window reduced the neutron flux intensity in the eV to keV energy range and significantly altered the spectral shape, while adjustments to the target slightly increased the neutron flux intensity in the eV to keV range and marginally modified the spectral shape. Additionally, by analyzing the neutron energy spectra under two different commonly used collimator configurations, the differences in their spectral shapes were also compared. This work provides essential data support for neutron capture cross-section measurements and related studies carried out at the Back-n ES#2. The datasets presented in this paper are openly available at https://www.scidb.cn/s/ArAvAn .
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To meet the demands for miniaturization and higher operating frequencies in self biased circulators, improving the performance of hexaferrite materials is essential. In this work, La–Zn–Sc co substituted M type barium ferrites (La0.3Ba0.7Fe10.9-xZn0.3ScxO19) were prepared via solid state reaction. X ray diffraction (XRD) confirmed the formation of a single phase magnetoplumbite structure in all samples. Scanning electron microscopy (SEM) images revealed that the ferrite particles exhibit hexagonal platelet morphology and are aligned along the c axis after wet pressing and sintering under a magnetic field. Lattice parameters and particle sizes were calculated from the XRD and SEM data. Magnetic measurements indicate that the Sc–La–Zn substituted M type ferrites exhibit high saturation magnetization (Ms > 60 emu/g) while allowing the magnetocrystalline anisotropy field to be tuned between 7–10 kOe via controlled Sc doping. Moreover, a narrow ferromagnetic resonance linewidth (ΔH ≈ 260 Oe) was achieved. Based on the measured magnetic parameters, three self biased circulators operating at center frequencies from 25 GHz to 35 GHz were designed and simulated using HFSS, demonstrating a broad frequency tuning range. The circulators exhibit a minimum insertion loss below 0.5 dB and a maximum isolation bandwidth (isolation >20 dB) of up to 4.4 GHz. This study highlights the potential of these materials for self biased circulators covering different frequency bands.
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Fe-based amorphous alloys have continuously attracted extensive attention due to their excellent soft magnetic properties, such as high saturation magnetization, high permeability, low coercivity, and low core loss. However, the theoretical studies on the magnetism of amorphous alloys remain incomplete, and the structural origins of the magnetic properties in Fe-based amorphous alloys are still unclear, making it difficult to fully explain their magnetic behavior. Accordingly, this review summarizes recent experimental and computational progress in exploring potential correlation mechanisms between amorphous structures and soft-magnetic properties. Existing research has primarily focused on how different elements affect the electronic structure, magnetic moment, saturation magnetization, and other properties of iron-based amorphous alloys. However, little effort has been devoted to the in-depth exploration into the underlying mechanisms of the local atomic structures, including short-range and medium-range order, influence magnetic properties. This review aims to provide a reference for further elucidating the structural origins of magnetic properties in Fe-based amorphous alloys, while also identifying key unresolved issues in future research.
, , Received Date: 2025-09-16
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The optical potential is a key tool for describing interactions in nuclear collisions and is widely used in studies of nuclear reaction mechanisms. It is highly sensitive to nuclear structure, leading to distinct characteristics between weakly bound and tightly bound nuclear systems.For weakly bound nuclei such as 6Li, 9Be and 6He, the behavior of the optical potential remains controversial due to insufficient experimental data at near-barrier and deep-barrier energies.In this work, elastic scattering angular distributions for the 6Li+208Pb system were measured at near-barrier and deep-barrier energies. Optical model fitting was employed to extract the optical potential parameters. The results indicate an anomalous threshold anomaly in the optical potential of this system, and the dispersion relation is not applicable. Furthermore, the reaction threshold for the 6Li+208Pb system was determined to be approximately 0.73VB based on deep-barrier data. A systematic analysis was also performed on the reaction thresholds and breakup thresholds of different nuclear systems.This work measured the optical potential of the 6Li+208Pb system at near-barrier and deep sub-barrier energies, providing data support for further investigation of the anomalous threshold anomaly.The datasets presented in this paper are openly available at https://www.doi.org/10.57760/sciencedb.j00213.00218 .
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On the basis of precisely treating various physical effects—including core-valence electron correlation, scalar relativistic, spin-orbit coupling, and extrapolation to the complete basis set limit, this study constructs the potential energy curves of 18 Λ-S states and the corresponding 35 Ω states of the SH+ ion by means of the optimized icMRCI+Q method. Within the all-electron icMRCI/cc-pCV5Z+SOC theoretical framework, the transition dipole moment curves of 12 pairs of transitions between 7 Ω states[including X3Σ-0+, X3Σ-1, (1)21st well(υ'=0–8), (2)0+(υ'=0–5), (2)21st well(υ'=0–2), (2)11st well(υ'=0–2), and (3)0+(υ'=0–2)] are calculated. Based on the aforementioned potential energy curves and transition dipole moment curves, the spectral data of each state and the transition data between Ω states are determined by solving the Schrödinger equation for nuclear motion and combining with the corresponding formulas, and the obtained results are in excellent agreement with the experimental values. In addition, the spectral characteristics of the 12 pairs of radiative transitions are clarified, the variation laws of the radiative lifetimes(τυ'J') and radiation widths(Γr) of the excited Ω states are revealed, and the influence of the rotational quantum number(J') on the radiative lifetimes(τυ'J') of the (2)21st well(υ'=0−2, +), (2)11st well(υ'=0–2, +), and (3)0+(υ'=0–2, +) states is discussed. The datasets presented in this paper, including the potential energy curves of 18 Λ-S and 35 Ω states, 12 pairs of transition dipole moments between the 7 Ω states[X3Σ-0+, X3Σ-1,(1)21st well(υ'=0–8), (2)0+(υ'=0–5), (2)21st well(υ'=0–2), (2)11st well(υ'=0–2), and (3)0+(υ'=0–2)], and variation of the radiative lifetimes(τυ'J') with J' for the (2)21st well(υ'=0−2, +), (2)11st well(υ'=0–2, +), and (3)0+(υ'=0–2, +) states of SH⁺ ion, are openly available at https://www.doi.org/10.57760/sciencedb.j00213.00233. (Data private access link https://www.scidb.cn/s/nMziqa)
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