Reaction pathway investigations of the solvothermal preparation of nanocrystalline Culn1xGa xSe2 in triethylenetetramine reveal the early formation of a previously unreported CU2-xSe(S) intermediate. Over 24 hours, this reacts with In and Se species to form CulnSe2(s). If Ga is present, the reaction proceeds over an additional 48 hours to form Culn1xGa xSe2. Adding ammonium halide salts reduces...

Amorphous and nanocrystalline silicon films obtained by Hot-Wire Chemical Vapor deposition have been incorporated as active layers in n-type coplanar top gate thin film transistors deposited on glass substrates covered with SiO2. Amorphous silicon devices exhibited mobility values of 1.3 cmVs, which are very high taking into account the amorphous nature of the material. Nanocrystalline transist...

Sparse arrays of evaporated silver nanodisks were fabricated with nanosphere lithography (NSL) on glass substrates and on hydrogenated nanocrystalline silicon solar cells. The optical transmittance spectra for arrays on glass vary substantially with film thickness, and were reasonably consistent with previous work. The quantum efficiency spectra of hydrogenated nanocrystalline silicon solar cel...

This paper presents a combination of the surface mechanical attrition treatment (SMAT) and the corolling process performed at 550 °C. This duplex method leads to the formation of a semi-massive multilayer structure of alternating nanocrystalline layers, transition layers and coarse grain layers. Transmission electron microscope observations correlated with nanoindentation hardness measurements ...

mechanical alloying of binary and ternary elemental powder mixtures with the nominal compositions of mg2ni and mg(2-x)mnxni (x= 0, 0.05, 0.10 and 0.15 at. %) were carried out in a planetary ball mill for various milling times of 5, 10, 15, 20, 30 and 60 h. x-ray diffraction and field emission scanning and transmission electron microscopy were used for the characterization of the milled products...

Nanocrystalline cadmium sulfide thin films as antireflection materials for solar cells have been prepared by a new chemical solution deposition route in an aqueous medium at 50 °C. as-deposited thin films were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and optical absorption spectra. X-ray diffraction data indicated the formation of hexagonal na...

The elastic and vibrational properties of iron-nickel and aluminum nanoparticles and nanocrystalline materials have been investigated on the basis of molecular dynamics simulations and the embedded atom method for the description of the materials. It is well known that nanocrystalline solids, with grain sizes in the nanometer range, exhibit often unsual properties like increased hardness due to...

Nanotwins in nanocrystalline Mg–Alalloys: an insight from high-resolutionTEM and molecular dynamics simulation Report Title Twinning in hexagonal close-packed Mg alloys has been reported to be unfavorable when the grain size is reduced below a couple of microns and suppressed at the nanoscale. Using high-resolution transmission electron microscopy, we present evidence of nanotwins (<1 nm) in na...

The exceptional properties of nanocrystalline materials lend themselves to a wide range of structural and functional applications. There is recent evidence to suggest that grain boundary impurities may have a dramatic effect on the stability, strength and ductility of nanocrystalline metals and alloys. In this study, transmission electron microscopy and atom probe tomography were used to charac...

The large fraction of material residing at grain boundaries in nanocrystalline metals and alloys is responsible for their ultrahigh strength, but also undesirable microstructural instability under thermal and mechanical loads. However, the underlying mechanism of stress-driven microstructural evolution is still poorly understood and precludes rational alloy design. Here we combine quantitative ...