ANALYSIS OF THE COORDINATION NUMBER OF THE ATOM W IN ZnWO4 SINGLE CRYSTALS

Abstract

The coordination number Z of the atom W in scintillator ZnWO4 is analyzed based on the X-ray structural data and Raman scattering experiment results. Z is suggested to be 6 that might be more reasonable than 4. t turns out that the luminescence center in ZnWO4 locates at the configuration of the atomic group WO6, instead of WO4-2. We also present some new Raman lines expected bytheoretical analysis.

Study on the Methods of the Surface Self-Nanocrystalline Technology and its Effect on the Materials Properties

“…The non-equilibrium thermodynamics is the technology that heating the surface of the material to the melt or phase changing temperature, and then cool fast to increase the nucleation rate to prevent the grain grow up, which can obtain nano organization on the surface. Methods such as laser heating and electronic radiation can achieve rapid heating-cooling [9].The mixed mode is to combine the surface self-nanocrystalline and chemical treatment, when nano surface structure form, do chemical treatment to the material to form solid solution or compound whose composition are different from the matrix on the surface. The chemical treatment is easy to go on, because the formation of the nanocrystalline organization make the volume fraction increase obviously, which give favors to the diffusion of the atoms and reduce chemical treatments' temperature and time and increase the concentration and depth of the elements, as a result, it is easier for the chemical treatment to go on at low temperatures [10].…”