The properties of nanocrystalline materials are essentially determined by the grain size and the properties of the grain boundaries of the respective material. Using PAC for the investigation of nanocrystalline materials new information about structural properties and, in case of nanocrystalline semiconductors, electronic properties are obtained. In combination with “classical” experimental tec...

for the first time this study reported the success of using nanocrystalline hexagonal close-packed (hcp) nickel (ni) modified composite graphite (cg) electrode (hcp-nano ni/cg) for the electrocatalytic oxidation of glycerol in alkaline medium (0.1 m koh). the hcp-nano ni/cg electrode had an improve response and specificity on the electrocatalytic oxidation of glycerol over the bare cg. the elec...

We review case studies of diffusion in nanocrystalline ceramics, i. e. polycrystalline non-metallic materials with average grain sizes typically in the range from 5 nm to 50 nm. The experimental methods applied are on the one hand tracer diffusion or conductivity methods which are sensitive to macroscopic transport, on the other hand NMR techniques which, complementarily to the previous ones, g...

We report transmission electron microscope observations that provide evidence of deformation twinning in plastically deformed nanocrystalline aluminum. The presence of these twins is directly related to the nanocrystalline structure, because they are not observed in coarse-grained pure aluminum. We propose a dislocation-based model to explain the preference for deformation twins and stacking fa...

Nanocrystalline (nc) materials can be defined as solids with grain sizes in the range of 1–100 nm. Contrary to coarse-grained metals, which become more difficult to twin with decreasing grain size, nanocrystalline face-centered-cubic (fcc) metals become easier to twin with decreasing grain size, reaching a maximum twinning probability, and then become more difficult to twin when the grain size ...

In this work, nanocrystalline Fe85Si10Ni5 soft magnetic powders were prepared by mechanical alloying and subsequent annealing to reduce the internal stresses and lattice strains. The powders were mixed with phenolic resin and warm pressed to produce nanostructured soft magnetic composites. The effect of annealing time and temperature on the crystalline structure, microstructure and magnetic pro...