Chemical state

About: Chemical state is a research topic. Over the lifetime, 2378 publications have been published within this topic receiving 78183 citations.

Synchrotron radiation studies of small particles and supported catalysts

Abstract: The authors used XAFS to determine the local structure around small CuO clusters on alumina, between room temperature and 400 degrees C. They measured the spectra at the copper and sulphur K edges to obtain information on the structure and chemical state of the clusters.

The chemical states of tellurium produced by spontaneous fission of252Cf

Abstract: The distribution of the chemical states of tellurium isotopes produced by252Cf spontaneous fission, collected separately in the matrixes of NaCl, Kl, NaF, CH3COONa·3H2O, Na2SO4 and NaNO3 crystals have been investigated Two chemical states of tellurium isotopes maintained in these matrixes are Te(IV) and Te(VI) The relationships between the distribution of the chemical states of tellurium isotopes and the produced mode of tellurium, the chemical properties of collection matrixes, the time for collecting fission fragments are studied and the possible mechanism of the interactions of the fission products and the matrixes is discussed The results show that the distribution of chemical states of tellurium isotopes depends on the chemical properties of the collection matrixes mainly

Chemical Form of Phosphorus-32 produced in Aluminium by Bombardment with Nitrogen

Abstract: MULTIPLY-CHARGED ions of elements up to neon have recently been accelerated to energies of the order of 100 MeV. in the Nuffield Laboratory 60-in. cyclotron at Birmingham1. Some of these ions have been used in bombardment studies2. Among the radioactive products is phosphorus-32, which is formed, for example, in relatively large yield in bombardments of aluminium-27 with 14N6+ ions. We have carried out experiments designed to show in what chemical state these atoms are held in the target.

Effect of the Chemical State of the Surface on the Relaxation of the Surface Shell Atoms in SiC and GaN Nanocrystals

Abstract: The effect of the chemical state of the surface of nanoparticles on the relaxation in the near-surface layer was examined using the concept of the apparent lattice parameter (alp) determined for different diffraction vectors Q. The apparent lattice parameter is a lattice parameter determined either from an individual Bragg reflection, or from a selected region of the diffraction pattern. At low diffraction vectors the Bragg peak positions are affected mainly by the structure of the near-surface layer, while at high Q-values only the interior of the nano-grain contributes to the diffraction pattern. Following the measurements on raw (as prepared) powders we investigated powders cleaned by annealing at 400C under vacuum, and the same powders wetted with water. Theoretical alp-Q plots showed that the structure of the surface layer depends on the sample treatment. Semi-quantitative analysis based on the comparison of the experimental and theoretical alp-Q plots was performed. Theoretical alp-Q relations were obtained from the diffraction patterns calculated for models of nanocrystals with a strained surface layer using the Debye functions.