MRS Communications最新文献

Memristors are utilized in nonvolatile memory and artificial synaptic devices. However, the industrial application of memristors has been restricted by the occurrence of fatigue, the mechanism of which is still under debate. In this paper, we systematically investigated the mechanism of defect generation created by Joule heating in Cu-doped TiO₂ memristive device. The results also demonstrated that the Joule heat for artificial synaptic emulation was less severe than that for digital data storage.

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Organic materials have found widespread applications but require doping to overcome their intrinsically low carrier concentration. Doping injects free carriers into the polymer, moving the position of the Fermi level, and creates coulombic traps, changing the shape of the electronic density of states (DOS). We develop equations to explicitly map the DOS parameters to the Seebeck vs conductivity relationship. At low carrier concentrations, this relationship is a universal slope (-{k}_{B}/q), while at higher carrier concentrations, the slope becomes dependent on the shape of the DOS. We conclude that, at high doping, a heavy-tailed DOS leads to higher thermoelectric power factors.

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LaAlO₃ nanofibers are prepared using reproducible and green electrospinning technique. Particularly, N,N-dimethylformamide (DMF) and acetic acid/water (A-A/W) were used as solvents. The structural and textural properties were compared. Results indicate that the diameter of as-spun nanofibers with (A-A/W) ranged from 50 to 400 nm. While it is between 100 and 600 nm for (DMF). After calcination, it decreased to an average of 80 nm for (A-A/W) and 200 nm for (DMF). Higher pore volume (0.69 cc g⁻¹) and surface area (176.3 m² g⁻¹) were achieved for (A-A/W) solvent. The textural properties confirm that LaAlO₃ exhibit high performances for advanced technologies mainly sensors.

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We described optical properties of zinc oxide (ZnO) nanoparticles determined by spectroscopic ellipsometry analysis from ex situ spectroscopic ellipsometry (ex situ SE) measurements made on nanocrystalline thin films over a spectral range of 0.734 to 4.00 eV. We determined the complex refractive index function, (widetilde{n}(omega )=n(omega )+ikappa (omega )), by fitting a layered parametric model to the ellipsometric measurements. We collected SE measurements at an incidence angle of 70°. We also determined absorption coefficient spectra using extinction coefficient, κ and wavelength, λ. The direct optical bandgap of the films was obtained as 3.2 eV using the ellipsometric method.

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This paper introduces and explains cyber physics, which we define as mathematical equations, i.e., physics-like laws, that control, regulate, or otherwise govern the inner workings of the hardware architecture, operating system, application code, algorithms, and networks on a classical computing machine. Cyber physics integrates computer science with conventional physics, in particular with quantum physics, thermodynamics, and statistical mechanics. Naturally, the technical description of cyber physics in the paper draws on both of these fields of science.

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By applying an aluminum coating to the copper-nickel alloy resistor, we successfully utilized air sintering. At 800 and 850°C, the alloy was sintered within an aluminum layer. This coating of aluminum serves as a protective layer. The copper-nickel was not oxidized as a result. After wet etching, the protective coating of aluminum was removed, leaving alloy resistors with Temperature Coefficient of Resistance (TCR) values of 417.86 ppm/°C. We produced an alloy paste using copper-nickel alloy (7:3) and then used screen printing to create thick-film alloy resistors. Therefore, it is feasible to create copper-nickel alloy resistors by air sintering.

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Additive manufacturing (AM) has many advantages over conventional subtractive manufacturing methods. The cost-effective AM allows for precise fabrication of complex structures with less material waste, making it a popular manufacturing process in many applications. The recent development of AM materials has advanced significantly. By precisely controlling material distribution and microstructural features, AM facilitates the creation of new composites with specific requirements. AM techniques have contributed considerably to integrating unique functionalities for various applications. This review emphasizes multiple categories of materials, including metal alloys, polymer-based composites, and sustainable composites, as well as applications of sensing materials and strategies and emerging artificial intelligence and machine learning.

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Methacrylation of Pluronics enables 3D printing of irreversible hydrogel constructs, thereby diversifying their potential applications. Current methods rely on organic solvents and time-consuming reactions. Herein, a rapid method for the microwave-assisted methacrylation of Pluronics by methacrylic anhydride (MA) in the absence of organic solvents is presented, which reduced the reaction time from 24 h to ca. 10 min. ¹H-NMR analysis showed that this method allows modulating the methacrylation degree (MD) of Pluronics from 45 to 97% by using different MA:Pluronic ratios. 3D-printed constructs with lower MD showed larger pores and lower compression modulus.

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This research investigates the effect of silicon (Si) addition on the phase transformation behaviour of the Ni–Ti alloy. The Ni–Ti–Si alloys were fabricated with varying proportions of Si through a modified vacuum induction melting technique with argon backfilling. Scanning electron microscopy, X-ray diffraction and differential scanning calorimetry were done to analyse the microstructure, elemental composition, and phase transformation temperatures, respectively, to validate the effectiveness of this modified melting technique. The results indicate an increase in the phase transformation temperature with an increase in the Si content in the alloy mixture and the alloys were prepared with a very minimal amount of detrimental impurities. This technique helps to produce high-temperature shape memory alloys with utmost purity which helps in retaining their functional properties. The transformation temperatures observed from differential scanning calorimetry revealed that the A_f temperature varies from 342.68 K to 379.95 K for 3 to 12% variation in Si content. This group of shape memory alloys have potential use as actuators in aircrafts and various other applications.

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Electrical impedance tomography is a method of mapping the conductivity distribution of a domain. For decades it has been considered a potential in situ nondestructive evaluation technique for characterization of conductivity changes in aerospace composites. Yet, several challenges must be addressed before this technique can be transitioned from the laboratory to meaningful practice; for example, the expense of the inverse problem that must be solved to estimate conductivity. An alternative is to characterize damage from the measured voltage-current relationship using deep learning. In this work, we develop and test a deep learning algorithm to characterize time-independent damage events in complex geometry.

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