MRS Communications最新文献

While efforts have been made to optimize organic semiconducting materials to achieve low-power-consumption organic field-effect transistors (OFETs), it is important to note that the choice of gate dielectric materials is equally critical. In general, a high-k polymer dielectric material is highly preferred for low-power-consumption OFETs. In this perspective, we highlight several newly emerged strategies for high dielectric constant polymer dielectrics. By exploiting the recent advances in molecular modulation and morphology control, these new strategies enable remarkably high dielectric constant up to 25–30 for polymer dielectrics, while still maintaining dielectric losses below 0.01 at 1 kHz. We further analyze the advantages and disadvantages of these strategies and propose four design principles—side-chain dipole, rigid free volume, self-assembly, and thermosets—for future polymer gate dielectrics in OFETs.

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This study examines the effects of Mn²⁺ doping on the microstructure, morphology, and thermoresistive properties of the Zn_x-1Mn_xO system (x = 0.8, 0.15 mol), synthesized via a combustion reaction. After uniaxial pressing (191 MPa) and sintering (1373 K), the samples exhibited NTC thermistor characteristics without a second phase. The decrease in the energy gap to 2.9 eV (Mn08) and 2.69 eV (Mn15), along with average particle sizes of 8.79 µm and 2.91 µm, respectively. The parameters α, β, A, B, C, and SF highlight the influence of Mn²⁺ doping on the properties of these materials, with potential applications in NTC thermistor devices.

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A series of titanium dioxide nanotubes were synthesized via a hydrothermal method. By varying the preparation conditions, nanotubes with different morphologies or textural properties were produced. Various characterization techniques were used to clarify the various features of the as-prepared nanotubes. Samples with surface areas ranging between 200 and 230 m²/g in specific surface area exhibit the maximum photocatalytic activity in the degradation of formic acid. Detailed analysis of the structural characteristics emphasizes the complex role played by surface structural defects in the tuning of their photocatalytic performance helping in this way to achieve optimal activity in photooxidation.

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An alloy based on the Laves phase, which hydrogenated at room temperature, and magnesium powder were used to create the composite material. Using the method of hydrogen dispersion, the alloy was crushed into a powder with a size of 30 μm. Composite materials were obtained by mixing magnesium with a size of 100 μm and the resulting powders from the alloy for 8 h, followed by pressing. This made it possible to obtain a new type of materials for hydrogen batteries, since they cannot be produced by the traditional casting method, because they do not have mutual solubility.

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Bridgman grown CsPbBr₃ single crystals have demonstrated γ-ray spectra with a high resolution, making them a highly promising competitor for the current benchmark room-temperature radiation detector Cd_1−xZn_xTe. However, CsPbBr₃ crystal growth is a very slow process that oftentimes results in cracked ingots due to phase transitions from cubic to orthorhombic crystal systems. In this report, we demonstrate the stabilization of a room-temperature cubic phase in Cs(Pb_1−xSn_x)(Br_3−yCl_y) solid solutions to overcome this issue. Cs(Pb_0.75Sn_0.25)(Br_1.00Cl_2.00) was identified as the most promising composition and grown as a crack-free ingot using Bridgman growth in around one week.

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This paper presents a groundbreaking strategy for optimizing composite laminate structures by integrating finite element modeling with a specialized multi-layer neural network. The neural network is trained on precise ground truth data obtained from rigorous finite element simulations, allowing it to discern intricate correlations among layer orientations, boundary conditions, and optimized designs. Tailored to the nuances of laminar composite optimization, the developed neural network emerges as a potent predictive tool, providing deep insights into the intricate interdependencies of design parameters. The study's findings hold immense promise for advancing materials design and structural engineering, highlighting the transformative potential of combining computational intelligence with traditional modeling approaches.

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Hybrids of carbon nanotube and metals have been regarded as promising candidate for flexible circuit, where thermal stability of nanograined metals is a challenging issue. In this study, we find thermal stability of Cu layer in CNT–Cu hybrids can be improved by coating Al₂O₃ layer. As for CNT–Cu hybrids, Cu nanograins are agglomerated during 673 K annealing. In contrast, the agglomeration of CNT–Cu hybrids can be suppressed after coating Al₂O₃ layer, and exhibit a thickness-dependent thermal stability after annealing at higher temperature. The underlying mechanism might be the compressive stress applied by Al₂O₃ coatings and inhibited diffusion along Cu/Al₂O₃ interfaces.

To address the issue of limited bone repair efficacy, a novel biomimetic HA/GT-OSA composite was synthesized through crosslinking gelatin (GT) with oxidized sodium alginate (OSA) for encapsulating hydroxyapatite (HA). The physicochemical properties of the composite were assessed using SEM, XRD, and FT-IR analyses. The biodegradability and biocompatibility of the HA/GT-OSA were confirmed via simulated body fluid (SBF) degradation testing and toxicity evaluation. Moreover, the HA/GT-OSA composites showed excellent bone regeneration performance in the SD rats intracranial bone repair, highlighting their immense potential for treating irregular bone defects and facilitating minimally invasive surgical implantation.

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Heteroatom doping of graphitic carbon is of high interest for tuning its physicochemical properties. Aluminum is commonly reported as a high-interest dopant, but few synthetic strategies have been reported owing to the low equilibrium solubility of Al within graphite. Herein we report several strategies to achieve metastable aluminum-substituted turbostratic graphitic carbon materials with aluminum contents up to ~ 0.5 at%, via co-pyrolysis of two molecular precursors between 800 and 1100°C. The resulting materials exhibit turbostratic graphitic structure and a previously unreported aluminum environment detectable by X-ray absorption spectroscopy (XAS), a likely signature of trigonal planar or puckered AlC₃-type sites.

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