Search

Antimony doped tin oxide (ATO) is an ideal material for thermal insulation. To obtain the stable performance of ATO nanodispersions and measure the transparent and thermal insulation properties of the ATO coatings, we investigated how a dispersant and sand milling affect the stability of ATO dispersion, which has come to the results that adding an appropriate dispersant and sand milling for 2.0 h were beneficial to the ATO dispersion. We characterized the morphology, nanostructure, particle size distribution, zeta potential, and optical properties of the ATO dispersions by a transmission electron microscope (TEM), a laser particle size analyzer, and a spectrometer. The results show that the average particle size of the dispersions is about 50 nm and their absolute values of all zeta potentials are more than 40 mV. We coated the thermal insulation water-based coatings on quartz glasses by spin coating method, the effect of thermal insulation is evident with the increase of the ATO content, and there exists approximately 10 °C difference between the ATO sample and blank sample with the condition for maintaining high transmittance of visual light. [ABSTRACT FROM AUTHOR]

BaTiO3–SnO solid solutions have been investigated from the viewpoints of synthesis and Sn ion valence. First-principles calculations show that the solution energy of Sn2+ into the Ba sites in BaTiO3 is less than that into the Ti sites under high pressure. The BaTiO3–SnO solid solutions have been synthesized under high pressure (∼20 GPa) and temperatures using a laser-heated diamond anvil cell. The synthesized materials have been characterized using x-ray diffractometry, scanning transmission electron microscopy, and energy-dispersive x-ray spectroscopy. It is found from these various methods that we have successfully synthesized uniform solid solutions of BaTiO3–SnO. Furthermore, it is also clarified by the Sn L3-edge electron energy loss spectra measurements that the valences of the Sn ions in the BaTiO3–SnO solid solution are 2+. These results indicate that the Sn2+ ions are substituted into the Ba sites, according to the ion size. Consequently, the Sn ions can be substituted into the Ba sites of the shrinking BaTiO3 lattice under high pressure, which is similar to the Ca and Sn co-substitution into Ba sites under ambient pressure as reported previously. [ABSTRACT FROM PUBLISHER]

We investigated how changes in the method of supplying Sn and Fe carbon nanocoil (CNC) catalysts affected the results of chemical vapor deposition. The Sn/Fe catalysts were supplied using the following four materials: a thin Sn film, a drop-coated solution of Fe2O3, tetramethyltin (TMT) vapor, and ferrocene vapor. The CNC purity was evaluated using scanning electron microscopy. The CNC purity in the overall carbon deposit was also evaluated by analyzing the cross-section of the deposit. The CNC purity averaged over the overall carbon deposit was increased 1.5-fold by the TMT supply. We obtained a maximum CNC purity of 72% using a combination of TMT and ferrocene vapors, with Sn/Fe deposition on the substrate. Energy-dispersive x-ray spectroscopy analysis of the catalyst nanoparticles in the tips of the CNCs and carbon nanofibers (CNFs) revealed that there was a large difference in the Sn/Fe molar ratios for the angular- and round-type CNFs. [ABSTRACT FROM PUBLISHER]

Branched core–shell hybrids of tin nanowires and carbon nanotubes have been successfully obtained on silicon substrate via a self-assembly process by chemical vapor deposition. Structure characterization unveiled that the nanostructures are the hybrids of branched single-crystalline β-Sn nanowires coated with amorphous carbon nanotubes. Detailed investigation demonstrates that the amount of introduced ethylene plays a crucial role in triggering the morphology change of the product from freestanding core–shell hybrids to branched hybrids accompanying with a thickness and surface morphology change of carbon shell. Architecture of the branched core–shell hybrids has been categorized and the mechanism has been discussed. This kind of branched hybrids may find great potential applications in building multipath nanoelectronic components, lithium-ion battery electrodes, and enhanced superconducting nanodevices as well. [ABSTRACT FROM AUTHOR]

The spontaneous whisker growth phenomenon was investigated by exposing Sn3Nd intermetallic compound (IMC) to different environments. In a humid environment, tin whiskers grew rapidly; the incubation time for whisker formation was only 0.75 h. However, no whiskers were formed when Sn3Nd IMC was exposed to dry argon for 33 days or dry oxygen (DO) for 7 days. In situ observation of whisker growth during room ambient (RA) exposure gave an average whisker growth rate of the Sn3Nd IMC of about 11 Å/s, which are 2–3 orders of magnitude faster than that previously reported for tin plating. Following whisker growth, a new hydroxide compound, Nd(OH)3, was found to have formed on the Sn3Nd. The results show that the presence of humidity in the exposure environment is necessary for whisker growth from Sn3Nd. Finally, the driving force for whisker growth is also discussed. [ABSTRACT FROM PUBLISHER]

Large-scale industrial production of carbon nanotubes (CNTs) has recently become available, but there are relatively few reports of the investigation of these industrially produced bulk CNTs as potential electrode materials for electrochemical energy storage such as lithium-ion batteries (LIBs). Here, we report our evaluation of the electrochemical performance of the industrially produced CNTs from one manufacturer and our utilization of a kinetically controlled, vapor diffusion synthesis method combined with in-situ carbothermal reduction to homogeneously grow nanocrystalline tin (Sn) particles (∼200 nm) in the matrix of the CNTs, yielding a Sn@CNTs composite. After surface coating with a layer of carbon coating (3–4 nm), this composite was transformed to a surface-modified Sn@CNTs composite that exhibited much higher reversible capacity, initial Coulombic efficiency, and rate capacity than the pristine CNTs as anode materials for LIB. [ABSTRACT FROM PUBLISHER]