The effects of sintering profiles on the densification behaviour of synthesized nanocrystalline hydroxyapatite (HA) powder were investigated in terms of phase stability and mechanical properties. A wet chemical precipitation method was successfully employed to synthesize a high purity and single phase HA powder. Green HA compacts were prepared and subjected to sintering in air atmosphere over a...

The evolution of size and size distribution during hydrothermal synthesis of nanocrystalline CoFe2O4 has been studied by in situ synchrotron powder X-ray diffraction (PXRD). Varying synthesis temperature or [OH(-)] concentration in the precursor proves to have no significant effect on the final volume-weighted nanocrystallite sizes (∼12 nm) of CoFe2O4. However, analysis by whole powder pattern ...

in this research, the high-energy planetary mill was employed to produce nanocrystalline ti-50al(γ)(at%) powders. initial powders were mechanically alloyed in 99.9999% and 90% purities of argon and also air atmosphere with alloying times up to 50h. the effect of impurity of argon atmosphere on the microstructure and the rate of phase transformation of ti-50al were investigated during mechanical...

The synthesis of NiO nanoparticles was done by sol-gel method. Nickel Acetate Tetrahydrate ((CH3COO)2 –Ni·4H2O) was dissolved in ethanol with constant stirring to obtain a clear and light greenish sol. Oxalic acid solution was used to obtain a thick green gel, then dried in an oven to get dried gel and was then grinded into fine powders and calcined for different time periods to obtain nanocrys...

Plastic deformation of nanocrystalline Fe was investigated by nanoindentation. Samples, synthesized by mechanical attrition, consisted of powder particles with diameters greater than 30 mm. The average grain diameters within the particles of different samples ranged from 10 nm to 10 mm. To avoid potential artifacts, samples were prepared without use of heat treatment, and measurements were cond...

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...

This study addresses the fabrication of nanocrystalline Fe–Co–Ni alloy using two operations: mechanical alloying (MA) of elemental powders and hot pressing (HP). The evolution of the phase composition and structure of the powder particles after MA was investigated. Ball milling with rotation speed 700 rpm for 15–20 min allows the production of a bcc Fe-based supersaturated solid solution. Durin...

The microstructure of three different nanocrystalline materials with hexagonal crystal structure are studied by X-ray diffraction peak profile analysis. The crystallite size distribution and the dislocation structure are determined in plasmathermal silicon nitride powder, sintered tungsten carbide and severely deformed titanium and are compared with transmission electron microscopy (TEM) result...

We demonstrate the application of a low-temperature carbon counter electrode with good flexibility and high conductivity in fabricating perovskite solar cells. A modified two-step method was used for the deposition of nanocrystalline CH3NH3PbI3 under high relative humidity. The carbon counter electrode was printed on a perovskite layer directly, with different sizes of graphite powder being emp...

Nanocrystalline Zinc Oxide (ZnO) powders with different morphology have been successfully synthesized by using different surfactants such as Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulphate (SDS), and Tri Ethanol Amine (TEA) via hydrothermal method. The products were characterized by means of powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electr...