Accession Number : ADP006424

Title :   Transparent Gel and Xerogel of Thorium Phosphate: Optical Spectroscopy With: Nd3+,Eu3+,Cr3+ and Rhodamine 6G,

Corporate Author : INSTITUT DE PHYSIQUE NUCLEAIRE ORSAY (FRANCE)

Personal Author(s) : Genet, M. ; Brandel, V. ; Lahalle, M. P. ; Simoni, E.

Report Date : MAR 1992

Pagination or Media Count : 7

Abstract : Chemical conditions for thorium phosphate gel preparation have been determined. The transparency is of good optical quality and the gel is very stable for a long time. Under drying condition, this gel can give rise to the xerogel which is still transparent. We can also prepare this xerogel by simple evaporation at room temperature of a very concentrated solution of thorium phosphate. From this viscous medium, the xerogel can be obtained in various kinds of shapes : threads, slabs and blocks. Solidification time depends on the final volume desired and spreads from few minutes to several weeks. Absorption spectrum of pure gel and xerogel have been recorded. Gel and xerogel doped with very well known probes like Nd3+ and Er3+ were examined to compare their optical properties with aqueous medium of the same chemical composition. Eu3+ doped gel and xerogel were also studied using their fluorescence properties. The optical properties of Cr3+ in doped gel and xerogel allowed us to determine the kinetics of hydration sphere modification during the drying period. Finally, as xerogel synthesis takes place at room temperature, fragile organic dye can be used as dopant, so Rhodamine 6G absorption and emission spectra have been studied in these conditions. When, at that time, the xerogel is doped with Coumarin 460 and Tb3+ an energy transfer is observed between dye and Tb3+ ions, which contributes to enhance the fluorescence of Tb3+ ions. Eu3+ behaves similarly. In conclusion, gel and xerogel of thorium phosphate tested with usual probes such as 3d, 4f ions and dyes seem to be very promising matrices.

Descriptors :   *OPTICAL PROPERTIES, *PHOSPHATES, ABSORPTION, CHEMICAL COMPOSITION, CHEMICALS, COUMARINS, DRYING, DYES, EMISSION, EMISSION SPECTRA, ENERGY, ENERGY TRANSFER, EVAPORATION, FLUORESCENCE, GELS, HYDRATION, IONS, KINETICS, MODIFICATION, PREPARATION, PROBES, QUALITY, ROOM TEMPERATURE, SOLIDIFICATION, SPECTRA, SPHERES, SYNTHESIS, TEMPERATURE, THORIUM, TIME, TRANSFER, TRANSPARENCIES, VOLUME.

Subject Categories : Optics
      Fluidics and Fluerics

Distribution Statement : APPROVED FOR PUBLIC RELEASE