MRS Communications最新文献

An unreported rhenium-based calcium aluminum sodalite (CARe sodalite) has been synthesized by a traditional solid-state method. The rhenium is located in the sodalite β-cage and can be reduced under 5% H₂ forming gas without breaking the cage framework. Preliminary characterizations of the structural, optical, and magnetic properties are reported.

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In view of the paradigm shift toward data-driven research in materials science and engineering, handling large amounts of data becomes increasingly important. The application of FAIR (findable, accessible, interoperable, reusable) data principles emphasizes the importance of metadata describing datasets. We propose a novel data processing and machine learning (ML) pipeline to extract metadata from micrograph image files, then combine image data and their metadata for microstructure classification with a deep learning approach compared to a classic ML approach. The ML model attained excellent performances with and without metadata and bears potential for performance improvement of further use cases within the community.

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We have designed a polymer, hc-TBtd-COP incorporating a Wurster-type redox-active building unit for the in situ reduction and nucleation of platinum nanoparticles which forms an organic polymer-wrapped metal nanoparticle composite. This composite exhibits exceptional mass activity (MA) (about 5 times larger than 20% Pt/C at 0.9 V vs. RHE) and specific activity (SA) (approximately 2 times larger than 20% Pt/C at 0.9 V vs. RHE) for the oxygen reduction reaction. The efficient electrocatalysis results from higher catalytic site dispersion and superior atom utilization efficiency. This research contributes to the advancement of composite materials for enhanced electrocatalytic performance.

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Short-fiber-reinforced polymer composites offer advantages, like flexibility in complex geometries and cost-effectiveness, but typically exhibit lower mechanical properties because of the random orientation of short fibers. In this work, a novel process utilizing shear force to create 3D scaffold with customized fiber alignment for the manufacturing of short carbon fibers (SCF)-reinforced thermoset composites has been presented. The Computed tomography test confirmed the alignment of the SCF along printing directions. The results demonstrate that the aligned SCF-reinforced epoxy composites exhibited a 190% improvement in tensile strength and 388% improvement in tensile modulus compared to neat epoxy.

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Co₃O₄ nanorods and nanosheets were prepared via a facile fluorine-mediated hydrothermal method, followed by thermal conversion. Both the Co₃O₄ nanorods and nanosheets exhibited a spinel structure, assembling by 30 nm nanograin along one and two dimensions. The primary exposed facet of the Co₃O₄ nanorods was identified as (110), while the main exposed plane of the Co₃O₄ nanosheets was (112). Gas sensing results showed the Co₃O₄ nanorods sensor exhibited higher sensitivity. The Co₃O₄ nanorods sensor demonstrated excellent sensitivities to toluene and xylene at 200°C, making it a promising candidate for the detection of these specific volatile organic compounds.

We present our findings on organic field-effect transistors (OFETs) that utilize the conjugated copolymer poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b′]-dithiophen-2-yl)alt[1,2,5]thiadiazolo[3,4-c]pyridine] as the active material, with electrodes composed of arrays of carbon nanotubes (CNTs). We employed three types of source and drain electrodes: gold, titanium, and CNT array electrodes with titanium contact pads. A comparison of characteristics of OFETs using these three different electrodes revealed the effectiveness of CNTs in enhancing charge carrier injection for OFETs. The OFETs based on CNT electrodes showed a twofold increase in the drain current and a threefold increase in charge carrier mobility compared to those with gold electrodes.

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With their remarkably low thresholds, organic polariton lasers are a promising alternative to organic photonic lasers. However, device stability remains a challenge, in part due to material degradation during deposition of the top dielectric mirror. We demonstrate polariton lasers based on 4,4′-Bis(4-(9H-carbazol-9-yl)styryl)biphenyl (BSBCz) as active material that achieve a low lasing threshold of 8.7 μJ/cm², and we show that a ZrO₂ protection layer between active layer and top mirror significantly improves stability. Optimized devices exhibit minimal degradation after 100,000 excitation pulses at 3.8 times above threshold. Our findings establish BSBCz as an attractive candidate for future injection driven polariton lasers.

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This study introduces a method to create porous carbon structures with intricate internal voids. 3D-printed PLA acts as an internal sacrificial template, combined with carbonized whey powder as the porous carbon matrix. Sintering whey powder at 150°C yields solid pieces that, upon carbonization, result in highly porous carbon objects while maintaining the original mold shape. Temperature control ensures successful whey powder sintering before PLA melting. The use of PLA sacrificial templates, along with whey carbonization, allows for developing devices with finely tailored internal voids, as demonstrated through a double Archimedean spiral reactor with porous carbon walls.

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We present the analytic workflow to understand the temperature and illumination-intensity-dependent recombination of the photoinduced charge carriers in organic–inorganic hybrid perovskite solar cells based on methylammonium lead iodide (CH₃NH₃PbI₃) thin films. The temperature-dependent, open-circuit voltage analysis reveals that the recombination of photoinduced charge carriers predominantly occurs at our PEDOT:PSS/CH₃NH₃PbI₃ interface as well as in the depletion region. Taking into account the structural phase transition in CH₃NH₃PbI₃ films, as confirmed using temperature-dependent x-ray diffraction spectra and dielectric constant measurements, the illumination-dependent short-circuit current and open-circuit voltage analysis shows both bimolecular and trap-assisted recombination is dominant in our solution-processed perovskite solar cells.