Science and Technology of Advanced Materials最新文献

The spontaneous Hall effect (SHE), a finite voltage occurring transversal to the electrical current in zero-magnetic field, has been observed in both conventional and unconventional superconductors, appearing as a peak near the superconducting transition temperature. The origin of SHE is strongly debated, with proposed explanations ranging from intrinsic and extrinsic mechanisms such as spontaneous symmetry breaking and time-reversal symmetry breaking (BTRS), Abrikosov vortex motion, or extrinsic factors like material inhomogeneities, such as non-uniform critical temperature (T_c) distributions or structural asymmetries. This work is an experimental study of the SHE in various superconducting materials. We focused on conventional, low-T_c, sharp transition Nb and unconventional, intermediate-Tc, smeared transition Fe(Se,Te). Our findings show distinct SHE peaks around the superconducting transition, with variations in height, sign and shape, indicating a possible common mechanism independent of the specific material. We propose that spatial inhomogeneities in the critical temperature, caused by local chemical composition variations, disorder, or other forms of electronic spatial inhomogeneities could explain the appearance of the SHE. This hypothesis is supported by comprehensive finite elements simulations of randomly distributed Tc's by varying T_c-distribution, spatial scale of disorder and amplitude of the superconducting transition. The comparison between experimental results and simulations suggests a unified origin for the SHE in different superconductors, whereas different phenomenology can be explained in terms of amplitude of the transition temperature with respect to Tc-distribution.

Capacitive Deionization (CDI) has emerged as an energy-efficient and environmentally friendly technology for water desalination. This review provides a comprehensive analysis of CDI, covering both experimental and simulation approaches. It introduces the background, definition, and diverse applications of CDI, from water desalination to environmental monitoring and resource recovery. The review highlights CDI's advantages, such as low energy consumption and operational simplicity, as well as its limitations, particularly its design-specific operating window favoring low-to-moderate salinity waters and sensitivity to organic-rich conditions. Strategies such as hybrid CDI systems and electrode surface functionalization are discussed to mitigate these challenges. Key working principles and advancements, including innovations in electrode materials, synthesis methods, and reactor design, are examined to improve ion removal efficiency, selectivity, energy use, and system durability. Material modification strategies are presented in the context of structure - performance relationships, emphasizing rational design principles. The review also explores simulation methods, including reactor modeling, computational fluid dynamics, molecular dynamics, and numerical approaches, and machine learning highlighting their synergy with experiments in optimizing CDI performance and guiding scale-up. Coupling CDI with other systems and its applications in water purification, particularly for ion and organic compound removal are also discussed. Finally, challenges in both experimental and simulation efforts, such as material cost, model complexity, computational demands, and scalability, are discussed. While CDI shows promise for sustainable water desalination and resource recovery, further research on hybrid configurations, predictive modeling, and pilot-scale validation is needed to address its limitations and enable large-scale adoption.

We measured the residual stress tensor in a nitrogen-doped chemical vapor deposition (001) diamond film. The stress tensor was evaluated from the amount of the shift in optically detected magnetic resonance (ODMR) spectra of NV center in the diamond. A confocal microscopy setup was used to observe the spatial variation of the stress tensor in the diamond film. We found that the components of the stress tensor, σ_xy, σ_yz, σ_zx and σ_xx+ σ_yy+ σ_zz, of the residual stress were approximately 0.077, -0.39, -0.67 and 1.52 GPa, respectively, in the x = [100], y = [010], z = [001] coordinate system. Regarding the components of the shear stress, σ_xy, σ_yz and σ_zx, the nitrogen-doped CVD diamond film grown in this study had mainly sheared stress in the z-direction, which was the growth direction of the CVD diamond film. In addition, regarding axial stress σ_xx+ σ_yy+ σ_zz, the CVD diamond film was subjected to compressive stress. Due to this compressive stress, the volume of the CVD diamond film decreased by approximately 0.073%. We considered that nitrogen doping contributed to the decrease in volume of the CVD diamond film.

The magnetocaloric effect (MCE) provides a promising foundation for the development of solid-state refrigeration technologies that could replace conventional gas compression-based cooling systems. Current research efforts primarily focus on identifying cost-effective magnetic materials that exhibit large MCEs under low magnetic fields across broad temperature ranges, thereby enhancing cooling efficiency. However, practical implementation of magnetic refrigeration requires more than bulk materials; real-world devices demand efficient thermal management and compact, scalable architectures, often achieved through laminate designs or miniaturized geometries. Magnetocaloric materials with reduced dimensionality, such as ribbons, thin films, microwires, and nanostructures, offer distinct advantages, including improved heat exchange, mechanical flexibility, and integration potential. Despite these benefits, a comprehensive understanding of how size, geometry, interfacial effects, strain, and surface phenomena influence the MCE remains limited. This review aims to address these knowledge gaps and provide guidance for the rational design and engineering of magnetocaloric materials tailored for high-performance, energy-efficient magnetic refrigeration systems.

Heat flux sensors based on the anomalous Nernst effect (ANE) have emerged as a promising solution for achieving thin and flexible designs. ANE-based heat flux sensors typically employ thermopile structures composed of two ANE materials with opposite signs, connected in series to enhance sensing performance. However, a mismatch in the Seebeck coefficient between the two ANE materials causes a considerable offset voltage due to the Seebeck effect (SE) under oblique heat flux. This parasitic sensing voltage hinders direct sensing of heat flux in the intended direction. In this study, a sign-reversed ANE with matched Seebeck coefficient is examined in Fe₃Ln (Ln = Gd, Tb, Dy, Ho, and Er), enabling a thermopile structure free from the SE-induced offset voltage. Based on density functional theory calculations, Fe₃Ln is selected as a suitable candidate for exhibiting sign reversal of ANE while maintaining the Seebeck coefficient. At 300 K, Fe₃Ln (Ln = Gd, Tb, Dy, and Ho) exhibits a positive ANE sign, whereas Fe₃Er exhibits a negative ANE sign, facilitating the combination of two sign-reversed ANE materials. Among these, Fe₃Ho and Fe₃Er demonstrate the lowest Seebeck coefficient difference of 0.45 μV K^-1, minimizing the offset voltage-induced relative uncertainty, as confirmed by COMSOL simulations - comparable to that of other SE-based heat flux sensors. This study paves the way for the development of ANE-based heat flux sensors by introducing a novel approach to pairing opposite-ANE-sign materials with matched Seebeck coefficient, enabling direct and accurate heat flux sensing via thermopile structures.

This paper examines the phonon dispersion and static local atomic distortion of iron-manganese-based Elinvar alloys using high-resolution inelastic X-ray scattering, magnetization, neutron diffraction, and neutron total scattering. In this study, nonlinear phonon dispersion was observed for a transverse acoustic mode near zone center, associated with $(C_{11}-C_{12})/2$ elastic constants, over a wide temperature range along the $\Gamma \left(220\right)$ to X (310) points of the face-centered cubic system, indicating lattice instability coupled with tetragonal distortions in the long-wavelength limit. Bulk magnetization and neutron diffraction measurements suggest that the conventional ferromagnetic magnetostriction scenario is not the origin of Elinvar characteristics. Instead, the martensitic transformation and lattice instabilities underlie these phenomena. The reduced pair distribution function reveals a significant discrepancy between local and global (averaged) structures suggesting the influence of atomic-scale lattice disorder and instability in FeMn-based Elinvar alloys.

This study explores the synergistic potential of PEG-b-P(L-Arg)-based polyion complex micelles (Nano^ARGs) combined with an immune checkpoint inhibitor (PD-1 antibody) for cancer immunotherapy. Comprehensive experiments, including micelle preparation, in vivo anti-tumor activity evaluation, nitric oxide (NO) quantification, and immunofluorescence analysis, revealed significant insights. Nano^ARGs exhibited a biphasic effect on tumor growth: high doses inhibited tumor growth through NO generated from liberated Arg, whereas low doses promoted tumor progression. The combination treatment demonstrated significant synergistic anti-tumor activity without notable adverse effects, and treated mice tolerated the regimen well. This approach elevated NO levels in serum and tumor tissues, enhanced immune cell infiltration into tumor tissues, and facilitated the polarization of tumor-associated macrophages to the M1 phenotype. PD-1 antibody further amplified these effects by blocking PD-1/PD-L1 interactions and reactivating T cells. These results underscore the therapeutic potential of this novel approach, providing a foundation for optimizing tumor immunotherapy strategies and advancing clinical applications. Future research will focus on elucidating the mechanisms of action and expanding the scope of this promising treatment.

The transverse thermoelectric generation and cooling performances in a thermopile module composed of recently developed SmCo₅/Bi_0.2Sb_1.8Te₃ artificially tilted multilayers are evaluated quantitatively. When a large temperature difference of 405°C is applied to the SmCo₅/Bi_0.2Sb_1.8Te₃-based module, the open-circuit voltage and output power reach 0.51 V and 0.80 W, respectively. The corresponding maximum power density is 0.16 W/cm², even if the power is normalized by the device area including areas that do not contribute to the power generation, such as epoxy resin, electrodes, and insulating layers. The maximum energy conversion efficiency for our module in this condition is experimentally determined to be 0.92%. Under the cooling operation, the same module exhibits the maximum temperature difference of 9.0°C and heat flow at the cold side of 1.6 W. Although these values are lower than the ideal thermoelectric performance expected from the material parameters due to the imperfections associated with modularization, the systematic investigations reported here clarify a potential of the SmCo₅/Bi_0.2Sb_1.8Te₃ artificially tilted multilayers as thermoelectric generators and cooling devices.

Current tumor therapies face significant limitations such as hypoxic microenvironments, systemic toxicity, and immunosuppression. Thylakoid-based nanomaterials strategically integrate the structural-functional properties of natural biological components with the versatility of nanotechnology. These biomaterials have garnered substantial scientific interest due to their promising therapeutic potential in oncology. Thylakoids perform essential biological functions including solar energy absorption, photolytic oxygen generation, and operation of photosynthetic electron transport chains. Harnessing thylakoid-specific photochemical properties through nanoscale hybridization offers an innovative paradigm for developing multifunctional platforms in oncotherapy. This review summarizes current challenges in tumor therapy and the advantages of thylakoid-based nanomaterials in addressing these limitations. We further examine recent advances in the engineering design of thylakoid-based nanomaterials and their therapeutic applications. Finally, we discuss existing challenges and future prospects in this field.