An anomalous dependence of the lattice parameter on the crystallite size of nanocrystalline ball-milled powders of metals was observed: lattice contraction followed by lattice expansion with decreasing crystallite size. These data were determined by application of detailed Xray diffraction measurements. To this end, the lattice parameters of all the metals were accurately determined by correcti...

High-resolution transmission electron microscopy (HRTEM) measurements of the thickness of white mica crystallites were made on three pelite samples that represented a prograde transition from diagenetic mudstone though anchizonal slate to epizonal slate. Crystallite thickness, measured normal to (001), increases as grade increases, whereas the XRD measured 10 ~ peakprofile, the Kubler index, de...

Microstructure of sintered nanocrystalline SiC is studied by x-ray line profile analysis and transmission electron microscopy. The lattice defect structure and the crystallite size are determined as a function of pressure between 2 and 5.5 GPa for different sintering temperatures in the range from 1400 to 1800 °C. At a constant sintering temperature, the increase of pressure promotes crystallit...

We report on the thermally induced changes of the nano-structural and optical properties of hydrogenated nanocrystalline silicon in the temperature range 200-700 degrees C. The as-deposited sample has a high crystalline volume fraction of 53% with an average crystallite size of ~3.9 nm, where 66% of the total hydrogen is bonded as identical withSi-H monohydrides on the nano-crystallite surface....

Evolution of the structural and magnetic properties of ZnFe1.95Yb0.05O4 nanoparticles, prepared via a high-energy ball milling route and exposed to further thermal annealing/heating, was assessed in detail and correlation of these properties explored. While as-prepared spinel nanoparticles possess a high degree of inversion, heating of the sample to ∼500 °C is found to rapidly alter the cation ...

Nanocrystalline zinc ferrite (ZFO) has been synthesized from metal acetylacetonates by microwave irradiation for 5 min in the presence of a surfactant. The as-prepared material is ZFO and has been subjected in air to conventional furnace annealing and to rapid annealing at different temperatures. Both annealing protocols lead to well-crystallized ZFO, with crystallite sizes in the range 8–20 nm...

The proton diffusion coefficients in an electrolytic manganese dioxide (EMD) electrode at various stages of the constant current discharge have been determined by means of AC impedance technique. The finite diffusion model was applied in the numerical fitting. The crystallite size of EMD was estimated from (1 1 0), (1 2 1) and (0 2 1) diffraction peaks with both Scherrer equation and Warren–Ave...

The influence of wood components and cellulose crystallinity on the thermal degradation behavior of different wood species has been investigated using thermogravimetry, chemical analysis and X-ray diffraction. Four wood samples, Pinus elliottii (PIE), Eucalyptus grandis (EUG), Mezilaurus itauba (ITA) and Dipteryx odorata (DIP) were used in this study. The results showed that higher extractives ...

Nanocrystalline lead selenide (PbSe) thin films were prepared on glass substrates by a chemical bath deposition method, using sodium selenosulfate (Na(2)SeSO(3)) as a source of Se(2-) ions, and lead acetate as a source of Pb(2+) ions. Trisodium citrate (TSC) was used as a complexing agent. PbSe films were prepared at various deposition temperatures while the pH value was kept fixed at 11, and t...