Current status of nanoscience research is briefly surveyed with special emphasis on monodisperse metal nanocrystals. Tunneling spectroscopy measurements on polymer protected magic nuclearity Pd561 nanocrystals have revealed single electron charging effects. Mesoscopic organizations resulting from self-assembly of these nanocrystals have been investigated. Giant clusters containing magic numbers...

First-principle calculations are used to explore the use of magnetic degrees of freedom in catalysis. We use the Vienna Ab-Initio Simulation Package to investigate both L1 0-ordered FePt and CoPt bulk materials and perform supercell calculations for FePt nanoclusters containing 43 atoms. As the catalytic activity of transition-metal elements and alloys involves individual d levels, magnetic all...

Nanocrystals of tadalafil, a poorly water-soluble drug, were successfully prepared by sonoprecipitation technique for improving the solubility and dissolution rate. Tween80 was selected as an efficient surfactant to inhibit aggregation in stabilization of drug nanocrystals. Response surface methodology based on central composite design (CCD) was utilized to evaluate the formulation factors affe...

in this study, hydroxyapatite (ha) nanocrystals have been synthesized via chemical precipitation technique. diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials and sodium hydroxide solution was used as the agent for ph adjustment. the powder sample was evaluated by techniques such as scanning electron microscope, transmission electron microscope, fourier ...

The development of nanocrystals has been intensively pursued, not only for their fundamental scientific interest, but also for many technological applications. The synthesis of monodisperse nanocrystals (size variation <5%) is of key importance, because the properties of these nanocrystals depend strongly on their dimensions. For example, the colour sharpness of semiconductor nanocrystal-based ...

High anisotropy, L1 0 , FePt nanoparticle assemblies consisting of 4 nm diameter particles are considered a potential data storage medium beyond 1 Tbit/in 2. However, annealing at temperatures >500°C is required to form the high anisotropy phase. Recently work on the evolution of FePt nanoparticle assemblies as a function of annealing temperature has shown that for T anneal > 650°C a substantia...

High resolution magnetic force microscopy (MFM) has been carried out on L1(0)-FePt dot arrays patterned by plasma modified nanosphere lithography. An ex situ tip magnetization reversal experiment is carried out to determine the magnetic domains and verify the imaging stability of MFM and the mutual perturbations between the magnetic tip and the sample. We have identified that the critical size ...