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 ...

A contemporary question in the intensely active field of periodic mesoporous organosilica (PMO) materials is how large a silsesquioxane precursor can be self-assembled under template direction into the pore walls of an ordered mesostructure. An answer to this question is beginning to emerge with the ability to synthesize dendrimer, buckyball, and polyhedral oligomeric silsesquioxane PMOs. In th...

Amorphous silicon film (α-Si) doped with uniform erbium (Er) impurities is deposited by laser ablation technology. High density silicon nanocrystals (nc-Si) can be formed after the rapid thermal annealing (RTA) process. The crystalline process can be explained as the “metal-induced nanocrystalline mechanism”, i.e., doped erbium atoms introduce additional strain in the amorphous silicon matrix a...

Article history: Received 10 February 2016 Received in revised form 22 May 2016 Accepted 8 June 2016 Available online xxxx The relationships betweenmicrostructure, controlled by alloying elements prone to grain boundary segregation, and electrical resistivity in sputtered nanocrystalline Cu were investigated. We find a non-monotonic dependence of themean grain size on solute concentration for b...

Nanocrystalline ceria has been synthesized by a non-hydrolytic method using organic solvent and precipitant. The effect of the source compound on final nanocrystalline powder was investigated. The cerium nitrate hexahydrate subjected to different vacuum/thermal treatments to get cerium source compound having different extent of water of crystallization. The nanoceria, synthesized from these com...