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Poly(vinylidene fluoride-co-hexafluoropropylene) (HFP) nanocomposites with layered silicate have been synthesized via the melt extrusion route. The intriguing nanostructure, crystalline structure, morphology, and thermal and mechanical properties of the nanocomposites have been studied and compared critically with pristine polymer. HFP forms intercalated or partially exfoliated nanostructure (or both) in the presence of nanoclay, depending on its concentration. The bombardment of high-energy swift, heavy ions (SHI) on HFP and its nanocomposites has been explored in a wide range of fluence. The nanoclay induces the piezoelectric β-phase in bulk HFP, and the structure remains intact upon SHI irradiation. SHI irradiation degrades pure polymer, but the degradation is suppressed radically in nanocomposites. The heat of fusion of pristine HFP has drastically been reduced upon SHI irradiation, whereas there are relatively minute changes in nanocomposites. The coarsening on the surface and bulk of HFP and its nanocomposite films upon SHI irradiation has been measured quantitatively by using atomic force microscopy. The degradation has been considerably suppressed in nanocomposites through cross-linking of polymer chains, providing a suitable high-energy, radiation-resistant polymeric material. A mechanism for this behavior originating from the swelling test and gel fraction (chemical cross-linking) as a result of SHI irradiation has been illustrated. [ABSTRACT FROM AUTHOR]

We report the liquid phase epitaxial growth of Zn3As2on InAs (1?1?0) substrates using 100% In solvent. The zinc concentration in the layers was varied by changing the zinc mole fraction in the growth melt from 3 × 10?3to 15 × 10?3, keeping all other growth parameters constant. Layers grown with 3 × 10?3, 5 × 10?3and 8 × 10?3?mole fractions of zinc seem to be polycrystalline, while layers grown with more than 8 × 10?3mole fraction of zinc resulted in highly oriented and single crystalline material. Composition of the epilayers was confirmed by energy dispersive x-ray microanalysis. Scanning electron microscopy was used to determine the thickness of the epilayers and the growth rate was calculated. Furthermore it was found that a linear dependence exists between the growth rate and the zinc mole fraction in the growth melt. Atomic force microscopy results reveal that the smoothness of the epilayers improve when the zinc concentration in the epilayer approaches the stoichiometric value of Zn3As2. Room temperature Hall measurements showed that the grown epilayers were unintentionally doped p-type with an increase in the carrier mobility and a decrease in the carrier concentration with respect to the increase in the zinc mole fraction in the growth melt. [ABSTRACT FROM AUTHOR]

We report on the effect of 80 keV Xe+ ion irradiation on the commercially available, sectioned 10B pencil-graphite specimens subjected to normal and oblique angle incidence of ions (θi = 0°–70°) and considering a fixed ion fluence of . The pristine and irradiated samples were characterized by powder x-ray diffraction, atomic force microscopy and Raman spectroscopy studies. Unlike pristine graphite and normal incidence cases, several ripple patterns can be visualized in the atomic force micrographs of the specimens irradiated with an oblique angle incidence. Moreover, apart from conventional G-band located at , a distinct diamond-like carbon (DLC) phase has been witnessed at in the Raman spectra of the graphitic specimens subjected to ion impact and for values of 50° and 70°. The formation of the DLC phase along with surface ripple formation would find numerous scopes while dealing with properties such as surface transport, field emission and mechanically hard coating in miniaturized devices. [ABSTRACT FROM AUTHOR]

We demonstrate a highly selective and reversible NO2 resistive gas sensor using vertically aligned MoS2 (VA-MoS2) flake networks. We synthesized horizontally and vertically aligned MoS2 flakes on SiO2/Si substrate using a kinetically controlled rapid growth CVD process. Uniformly interconnected MoS2 flakes and their orientation were confirmed by scanning electron microscopy, x-ray diffraction, Raman spectroscopy and x-ray photoelectron spectroscopy. The VA-MoS2 gas sensor showed two times higher response to NO2 compared to horizontally aligned MoS2 at room temperature. Moreover, the sensors exhibited a dramatically improved complete recovery upon NO2 exposure at its low optimum operating temperatures (100 °C). In addition, the sensing performance of the sensors was investigated with exposure to various gases such as NH3, CO2, H2, CH4 and H2S. It was observed that high response to gas directly correlates with the strong interaction of gas molecules on edge sites of the VA-MoS2. The VA-MoS2 gas sensor exhibited high response with good reversibility and selectivity towards NO2 as a result of the high aspect ratio as well as high adsorption energy on exposed edge sites. [ABSTRACT FROM AUTHOR]