Carbon-coated silicon nanowires (C-Si NWs) were prepared as anodes for lithium-ion batteries (LIBs). The C-Si NWs were synthesized using a simple and effective fabrication strategy via magnesiothermic reduction. The synthesis sequence of carbon coating before the chemical etching of the reduced Si NWs/MgO composite was found to be critical for improved battery performance. In addition, carbon coating was found to help to stabilize the solid electrolyte interphase layer during battery cycling, which is important to realize the benefits of Si-based LIBs. This synthesis method provides an efficient route to synthesizing high-performance Si electrodes via magnesiothermic reduction.

NV centers in silicon carbide have been identified in the three main polytypes 3C, 4H, 6H by magnetic resonance and photoluminescence experiments and related ab initio calculations. Their properties show them to be promising centers for applications in quantum technology, similar to the case of NV in diamond. However, their spectral range is in the near-infrared, which should allow their integration in telecommunication systems.

This work investigates the antifungal effect of plasma polymer films produced by low-pressure RF-generated plasma system using acrylic acid, 2–hydroxyethyl methacrylate, and diethyl phosphite (DEP). Unmodified and plasma-modified polystyrene (PS) microplate wells were tested by 30 biofilm-positive Candida spp. isolated from blood samples and two control strains using a quantitative plaque assay method. Regardless of the precursors and plasma parameters, biofilm formation was inhibited for all plasma-modified microplate wells. The most significant anti-biofilm effect was observed on PS modified by DEP at 90 W plasma power with the inhibition of all Candida species’ biofilm formation.

Unlike other data intensive domains, understanding distributions, trends, correlations, and relationships in materials data sets typically involves navigating high-dimensional spaces with only a limited number of observations. Under these conditions extracting structure/property relationships is not straightforward and considerable attention must be given to the reduction of feature space before predictions can be made. Here we have used Kohonen networks (self-organizing maps) to identify hidden structure/property relationships in computational sets of twinned and single-crystal diamond nanoparticles based on structural similarity in multiple dimensions, and confirmed the importance of a limited number of surface chemical features using regression.

The use of copper hydroxyphosphate (Cu2PO4OH), also called libethenite, as a near-infrared (NIR) absorbing additive has been investigated. Samples were synthesized by using a hydrothermal treatment or simple wet chemical processing, which was later easily upscaled. All synthesized samples showed a strong absorption in the NIR region. Trials were conducted to produce laser-marked plastic plates and security IR ink printing tests. It was found that when incorporated in plastic and ink formulation, Cu2PO4OH added good NIR absorption properties without influencing other finished product properties too much, which confirms that it is a suitable additive that can be readily manufactured at room temperature and without pressured equipment.

Sinnerite (Cu6As4S9) is a semiconductor computed to have attractive optoelectronic properties, but little attention has been paid to its experimental synthesis and characterization. Here, the authors report the first synthesis of polycrystalline sinnerite thin films. By heating Cu3AsS4 nanoparticles in sealed ampoules with As2S2 powder, a phase transformation to Cu6As4S9 is achieved along with the formation of micron-sized dense grains appropriate for device applications. The films display a bandgap of ~1.2 eV, significant photocurrent generation under simulated AM1.5 illumination, and carrier lifetimes nearing 1 ns, demonstrating the promise of sinnerite for use in photovoltaic applications.

A new theta geometry was developed for microscale bending strength measurements. This new “gap” theta specimen was a modification of the arch theta specimen that enabled microscale tensile testing. The gap theta specimen was demonstrated here on single-crystal silicon, microfabricated using two different etch processes. The resulting sample strengths were described by three-parameter Weibull distributions derived from parameters determined using established arch theta strengths, assuming a specimen-geometry and -size invariant flaw distribution and an approximate loading configuration.

Two different sized As(0) nanoparticles As1 (50 ± 7 nm) and As2 (70 ± 10 nm) are prepared by reducing arsenite with NaBH4 in the pH range 7–9, at controlled temperature (10 and 40 °C). Further, galvanic replacement reaction is used exploiting the reducing nature of As(0) to prepare two different sized hollow gold nanoparticles (HGNPs) AuNP1 (55 ± 7 nm) and AuNP2 (72 ± 7 nm). These HGNPs exhibit high catalytic activity towards 4-nitrophenol reduction under various conditions following first-order kinetics. AuNP1 shows ~6.6 time higher turnover frequency compared with that of AuNP2 due to its smaller size. Both catalysts are recycle able.

The rise of additive manufacturing (AM) has enabled the rapid production of complex part geometries across multiple material domains. To date, however, AM of inorganic semiconductor materials has not been fully realized due to the difficulty of forming single-crystal materials with traditional AM processes. Here, we demonstrate a novel semiconductor synthesis method using a combination of liquid and gas precursors to additively print gallium nitride. Growth rates of 1–2 µm/min are demonstrated in printed regions while maintaining epitaxial alignment with the substrate. We also outline critical variables for the future development, improvement, and implementation of the proposed process.

Nitric oxide (NO) acts a pivotal role in regulating various physiological processes of vasodilation, platelet aggregation, and vascular smooth muscle cell mitogenesis and proliferation. This makes NO a promising candidate for the treatment of cardiovascular problems like hypertension and vascular stenosis. However, the high reactivity of NO poses an issue for effective NO delivery. To overcome this limitation, recent developments on three-dimensional (3D) materials have been explored with either physical or chemical incorporation of NO releasing donors, to provide spatiotemporal control over NO-signaling pathways in blood vessels. Here, we offer an overview on the current efforts, and propose future perspectives for precise regulation on NO delivery in advanced 3D materials toward proper vascular functionality.

In this work, the effect of temperature, in the range of 25 to 250 °C, on deformation twinning in textured polycrystalline pure magnesium (Mg) was investigated. Compression loading was applied perpendicular to the c-axis texture direction. The yield strength and strain hardening rate are shown to drastically decrease with increasing temperature with total suppression of twinning at 200 °C. This behavior is attributed to the decrease in the critical resolved shear stress for prismatic slip and temperature insensitivity of tensile twinning. These results provide a first step in fundamentally understanding the deformation of Mg at elevated temperatures and quantify the mechanisms that lead to their improved formability at elevated temperatures.

BiFeO3 (BFO) p-type semiconducting nanofibers were deposited on fluorine-doped SnO2 substrates by a combination of electrospinning (BiFeO3) and spin-coating (Fe2O3) procedures. Photocurrent density values of BFO nanofibers which increased with the annealing temperature to values six times larger were obtained. Different amounts of BFO nanofibers (5, 10, and 25 wt%) were also integrated into α-Fe2O3 films. The photocurrent density of the α-Fe2O3/BFO nanofiber films had the highest value for a 10 wt% BFO nanofibers. The anisotropy in charge transport due to the underlying nanofibrous pathways which prevented the charge carrier recombination was the main cause for the enhancement of the photocurrent density.

Tracing the flow of solid matter during an explosion requires a rugged tag that can be measured by a unique identifiable signature. Silica-covered semiconductor quantum dots (QDs) provide a unique and tunable photoluminescent signature that emits from within a sacrificial outer layer. Five types of silica-covered zinc sulfide QDs were synthesized and covalently bound to commercial luminescent powders. The combination of five dots and five powders enables a matrix of 25 unique tags. The tracers are shown to be tolerant of environments associated with chemical explosives and provides a unique tag to evaluate debris fields.

To identify new face centered cubic high entropy alloys (HEAs), MnFeCoNiCu thin film samples were prepared by simultaneous magnetron sputtering of elements onto Si wafers. This sputtering arrangement yielded compositional gradients in the samples. The films exhibited regions with different phases, some of which were single-phase and non-equiatomic. To screen the crystal structure and composition across film samples, multiple characterization techniques were used: scanning electron microscopy, focused ion beam, energy-dispersive x-ray spectroscopy, x-ray diffraction, and electron backscattered diffraction analysis. Using this combinatorial method, candidate single-phase HEAs were identified and then successfully arc-melted in bulk form, followed by thermomechanical processing.

We demonstrate formation of allylamine (AAm) and acrylic acid (AAc)-functionalized colloidal silicon nanocrystals (Si NCs) exhibiting near-infrared (NIR) luminescence and immobilization of the NCs on substrates via covalent bond. The surface functionalization is confirmed by IR absorption spectroscopy and specific binding property of functionalized NCs. Atomic force microscope observations reveal that AAm- and AAc-functionalized Si NCs are chemically immobilized on self-assembled monolayers via covalent bonds. The functionalized Si NCs exhibit photoluminescence in a NIR region (1.5–1.6 eV), which is not significantly affected by the functionalization.

This work demonstrated the possibility to integrate electrochemical molecularly imprinted polymers (e-MIPs) on microelectrodes to detect organic pollutants. e-MIPs are a cross-linked polymer with specific target binding cavities with a redox tracer inside. e-MIPs were obtained by precipitation copolymerization of ferrocenylmethyl methacrylate as a functional monomer and a redox tracer with ethylene glycol dimethacrylate as a cross-linker and bisphenol A as a target molecule. FTIR and elemental analysis confirmed the presence of ferrocene inside the polymers. Nitrogen adsorption/desorption experiments and binding isotherms demonstrated the presence of binding cavities inside the e-MIP. The electrochemical properties of the e-MIP were characterized in organic/aqueous media before their patterned on microelectrode.

Highly graphitic carbons are obtained by precipitating carbon from molten steel inoculated with bismuth. Scanning electron microscopy images show that the products have a potato peel morphology. The inoculant leads to a breaking of the local symmetry of the graphitic structure as evidenced by Raman spectroscopic studies. The products exhibit flat charge–discharge profiles below about 200 mV versus Li+/Li, reversible capacities even exceeding the theoretical limit of 372 mAh/g for perfectly graphitic structures, low first-cycle irreversible capacities, and sustained hundreds of cycles.

Spherical Sn0.3Ag0.7Cu (wt.%) solder droplets with diameter ranging from 70.6 to 334.0 µm were prepared using pulsated orifice ejection method. Compared with conventional atomization, these droplets are almost completely spherical with a much narrower size distribution. The surface of these droplets is smooth without detectable satellite particles. Furthermore, both the composition and microstructure are homogenous throughout any single droplet regardless of their size. Detailed microstructural analysis shows that nano-sized Ag3Sn particles are distributed homogenously in the β-Sn matrix. The results suggest that the droplets have advantage as electronic packaging material and be a promising candidate material for three-dimensional printing.

The role of substrate orientation on interface registry and nanocrystal shape has been investigated for epitaxial manganese oxide (Mn3O4) nanocrystals. Mn3O4 (101) nanoplatelets and (112)-orientated nanowires have been successfully deposited on (111) and (110) SrTiO3 (STO) substrates, respectively. Under higher magnifications, the (101) platelets were found to exhibit step-like growth, spiraling outward from a local dislocation site at the Mn3O4–STO interface. Selected area electron diffraction analysis from transmission electron microscope (TEM) was carried out to determine the in-plane edge directionalities of (101) and (112) Mn3O4. We found the (101) Mn3O4 orientation to exhibit a complex in-plane epitaxial relation of $[2\overline {31} ]$Mn3O4//[100]STO and an out-of-plane relation of $[\overline 1 01]$Mn3O4//$[\overline 1 11]$STO. Furthermore, lattice misorientations of 58° in-plane and 35° out-of-plane have been calculated, attributed to the shear caused by the spiral growth. For the (112) Mn3O4 nanowires, the TEM diffraction pattern indicates pyramidal cross-sections based along $[0\overline {11} ]$ STO. Subsequent calculations reveal that the (112) nanowires have their long axis (c-axis) such that [001]Mn3O4//[110]STO. Thus the nanowires grow preferentially along its longest axis giving rise to the observed shape and anisotropic nature.