a  facile  effective  stirring  aging  at  room  temperature  prior  to  conventional  hydrothermal treatment was employed in the template-free synthesis of micro- and nano-crystalline sodalites with  two  different  initial  gel  compositions.  the  effect  of  initial  si/al  molar  ratio,  naoh concentration and stirring aging time were investigated on the morphology and particle size of the...

Most new materials are introduced by selectively comparing their properties against those of steels. Steels set this standard because iron and its alloys have so much potential that new concepts are discovered and implemented with notorious regularity. In this 52nd Hatfield Memorial Lecture, a remarkably beautiful microstructure consisting of slender crystals of ferrite, whose controlling scale...

Thin film Ni-Cu diffusion couples (individual layer thicknesses: 50 nm) were prepared by direct-current magnetron sputtering on silicon substrates. Interdiffusion and solid-solution formation, the associated changes of microstructure and the evolution of mechanical stresses of the Ni-Cu diffusion couples during thermal treatments were investigated employing ex-situ X-ray diffraction phase and t...

Four principal factors contribute to grain-boundary strengthening: (a) the grain boundaries act as barriers to plastic flow; (b) the grain boundaries act as dislocation sources; (c) elastic anisotropy causes additional stresses in grain-boundary surroundings; (d) multislip is activated in the grain-boundary regions, whereas grain interiors are initially dominated by single slip, if properly ori...

with a mean grain size below 100 nm. Fig. 1 shows an image taken in a transmission electron microscope of a high-density nanocrystalline (nc)-Cu sample with a mean grain size of 20 nm. The mechanical behavior of a fully-dense nanocrystalline metal is, compared with its coarse-grain counterpart, characterized by a significantly enhanced yield stress and a limited tensile elongation1,2. A simple ...

The role of nanocrystalline materials in addressing the current challenges in energy storage has attracted large attention. Besides nanostructured B-type TiO 2 [1], being the fifth polymorph of titanium dioxide, Li intercalated nanocrystalline rutile is considered to act as a potential anode in inherently safe secondary Li ion batteries. In contrast to its coarse-grained counterpart, which is e...

The awareness of environmental factors, limited energy resources, and increasing energy demands have driven the search for both improved utilization of our fossil energy and new alternative energy resources. These new energy technologies are preferably cleaner, cheaper, smaller and more efficient than those currently being employed, for instance fuel cells, lithium-ion batteries, thermoelectric...

The mechanism of enhancing the light harvesting efficiency of dye-sensitized TiO(2) solar cells by coupling TiO(2) inverse opals or disordered scattering layers to conventional nanocrystalline TiO(2) films has been investigated. Monochromatic incident photon-to-current conversion efficiency (IPCE) at dye-sensitized TiO(2) inverse opals of varying stop band wavelengths and at disordered titania ...

Low-dimensional cuprous nitride (Cu3N) was synthesized by nitridation (ammonolysis) of cuprous oxide (Cu2O) nanocrystals using either ammonia (NH3) or urea (H2NCONH2) as the nitrogen source. The resulting nanocrystalline Cu3N spontaneously decomposes to nanocrystalline CuO in the presence of both water and oxygen from air at room temperature. Ammonia was produced in 60% chemical yield during Cu...