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A large-scale sub-5 nm nanofabrication technique is developed based on double layer anodized aluminium oxide (AAO) porous membrane masking. This technique also provides a facile route to form multilayer nano-arrays (metal nanoarrays sandwiched by AAO membranes), which is very challenging for other techniques. Normally the AAO mask has to be sacrificed, yet in this work it is preserved as a part of the nanostructure. The preserved AAO layers as the support for the second/third layer of the metal arrays provide a high-refractive index background for the multilayer metal arrays. This background concentrates the local E-field more significantly and results in a much higher Surface-Enhanced Raman Spectroscopy (SERS) signal than single layer metal arrays. This technique may lead to the advent of an inexpensive, reproducible, highly sensitive SERS substrate. Moreover, the physical essence of the plasmonic enhancement is unveiled by finite element method based numerical simulations. Enhancements from the gaps and the multilayer nanostructure agree very well with the experiments. The calculated layer-by-layer electric field distribution determines the contribution from different layers and provides more insights into the 3D textured structure.

Due to their unique physical and chemical properties, wide bandgap semiconductor materials have shown great potential in the field of optoelectronic devices, and have received more and more research and attention. Zinc gallate (ZnGa2O4) is a wide bandgap semiconductor material, showing broad application prospects in the fields of solar-blind ultraviolet photoelectric detection and X-ray detection for its wide bandgap, unique structure and good thermal stability. In this paper, based on the basic structural characteristics of ZnGa2O4, the bandgap, photoelectric properties of ZnGa2 O4, the preparation methods of ZnGa2O4 bulk single crystal and thin film are introduced in detail. Combined with the recent research results of domestic and foreign scholars, the application prospects of ZnGa2 O4 in many fields are summarized, especially the research progress of solar-blind ultraviolet photoelectric detection, memristor, X-ray detection and power devices. Finally, the future development direction of ZnGa2O4 is prospected, and it is pointed out that the quality and performance of ZnGa2O4materials can be further improved to improve device performance and meet higher level application requirements. [ABSTRACT FROM AUTHOR]

The selective oxidation of alkylarene is a quite straightforward and appealing way for production of aromatic aldehydes, ketones and aromatic acid derivatives. We synthesized Cr(III) catalyst, (NH4)3[CrMo6O18(OH)6], with reasonable activity towards selective oxidation of alkylarenes under mild conditions. The catalyst is supported by a central chromium mononucleus and a cyclic inorganic ligand composed of six MoVIO6 octahedra, avoiding the disadvantages of expensive and non‐recyclable organic ligand. It is efficient, green and can be recycled at least six times with high activity. At the same time, a wide range of substituted alkylarenes were found to be compatible, providing the corresponding carbonyl compounds in moderate‐to‐high yield. [ABSTRACT FROM AUTHOR]

The solid‐state nuclear optical clock based on 229Th‐doped crystal has great advantages in frequency stability, excitation and detection of nuclear transition, miniaturization, commercialization, and spaceborne ability of nuclear optical clock. Here, the potential of LiF crystal as a host for Th ions is predicted by theoretical calculation, and on this basis, the Th:LiF crystal is successfully grown experimentally for the first time. The theoretical results demonstrate that although the challenges of charge nonconservation and ion radius mismatch between Li+ and Th4+ ions exist, effective doping of thorium can still be achieved via energetically favorable charge compensation mechanisms in an F‐rich environment, and the transmittance of Th:LiF crystal in nuclear transition band will only have a slight decrease, smaller than that of pure LiF crystal. The experimental results prove that the doping concentration of Th:LiF crystal can reach about 8.3 × 1018 cm−3 and the transmittances of 1 mm thick Th:LiF and pure LiF crystal samples grown in similar conditions are ≈68% and 72% at 152.7 nm, respectively. The Th:LiF crystal with high doping concentration, high transmittance, and low background luminescence is expected to be a promising candidate for solid‐state nuclear optical clock materials. [ABSTRACT FROM AUTHOR]

The application of diamonds for thermal management of solid-state lasers has recently attracted increasing interest. However, the problem of synthesizing high-performance diamonds has not been addressed, hindering the development of advanced heat management. Here, we deposited diamond by a microwave plasma chemical vapor deposition (MPCVD) method on a Ti:sapphire substrate to improve the thermal performance of the substrate by using a Cr interlayer, and the seeded Cr layer was effective in improving the adhesion between the diamond film and the substrate. The results were rationalized by using first-principles calculations, and it was shown that the stable interface adhesion was attributed to the strong carbon adsorption capability of the Cr surface, which favored the C–Cr bond formation at the interface. The catalysis of Cr results in an increase in the non-diamond phase, impeding interface binding. To address this, ∼0.2% oxygen was used during the deposition process. Raman spectroscopy showed that the diamond film deposited on the Cr interlayers was under compressive stresses of 1.46 and 0.97 GPa, and the thermal diffusion coefficient increased by 17%. This enhancement in performance offers a promising potential for the fabrication of high-power solid-state laser heat spreaders using diamond films. [ABSTRACT FROM AUTHOR]

Herein, we reported the efficient method for synthesis of aldehydes, ketones and carboxylic acids from olefins catalyzed by inorganic‐ligand Fe (III) catalyst, (NH4)3[FeMo6O18(OH)6]. This transformation features sustainable conditions and utilizes commercially available H2O2 as the sole oxidant and CH3CN/ AcOH as the solvent. The simple synthesized catalyst has high efficiency towards the reactions under mild conditions and can be recycled at least six times with keeping stable activity. At the same time, the controllable products in the reaction have the potential for industrial application. [ABSTRACT FROM AUTHOR]

CeSb2 is a homologue of rare-earth diantimonides. This work reports a systematic study of a series of high-quality single crystals of CeSb2 grown by a self-flux method, which is a heavy fermion Kondo metal with intricate magnetic transitions. We have grown four types of crystals with different initial material ratios in order to investigate the effect of growth conditions on the quality of the as-grown crystals. The phase purity, morphology and composition of the synthesized samples were studied with X-ray diffraction, scanning electron microscopy, electron-probe microanalysis, and Raman-scattering spectroscopy to evaluate their quality. It is found that an inappropriate raw material ratio will lead to the inhomogeneity and poor crystallinity of the as-grown crystal. In addition, the electrical transport properties of the as-grown crystals were measured, from which the residual resistivity ratios were extracted to further examine the homogeneity and crystalline quality. Furthermore, the magnetoresistance properties of CeSb2 were observed. Through a systematic study on CeSb2, the most suitable starting ratio for the growth of CeSb2 was obtained, which might serve as a guide for the growth of other light rare-earth diantimonides. [ABSTRACT FROM AUTHOR]

Due to their unique physical and chemical properties, wide bandgap semiconductor materials have shown great potential in the field of optoelectronic devices, and have received more and more research and attention. Zinc gallate (ZnGa2O4) is a wide bandgap semiconductor material, showing broad application prospects in the fields of solar-blind ultraviolet photoelectric detection and X-ray detection for its wide bandgap, unique structure and good thermal stability. In this paper, based on the basic structural characteristics of ZnGa2O4, the bandgap, photoelectric properties of ZnGa2 O4, the preparation methods of ZnGa2O4 bulk single crystal and thin film are introduced in detail. Combined with the recent research results of domestic and foreign scholars, the application prospects of ZnGa2 O4 in many fields are summarized, especially the research progress of solar-blind ultraviolet photoelectric detection, memristor, X-ray detection and power devices. Finally, the future development direction of ZnGa2O4 is prospected, and it is pointed out that the quality and performance of ZnGa2O4materials can be further improved to improve device performance and meet higher level application requirements. [ABSTRACT FROM AUTHOR]