Accession Number : ADA290260

Title :   Synthesis And Application Of Large Heterometallic Cluster System.

Descriptive Note : Final interim rept. no. 10.

Corporate Author : TRINITY COLL DUBLIN (IRELAND)

PDF Url : ADA290260

Report Date : 15 FEB 1994

Pagination or Media Count : 49

Abstract : This three year project was concerned with the chemical synthesis of nanometric particles, related structures, and their application in nonlinear optics. Significant progress was made in all areas, i.e. Chemical Synthesis: Routes were developed to novel heterometallic assemblies. For details see 6th Interim Report (March 1993). Synthesis of polymers with nonlinear properties enhanced by incorporating metal units. For details see 5th Interim Report (August 1992) and earlier reports. Fullerenes were synthesized by recessive heating of graphite, and the apparatus and techniques modified to optimize yields and separation. See 3rd Interim Report (August 1991). Metallo Fullerene species have been synthesized, characterized (see attached publication in press) and their nonlinear properties measured; see 9th Interim Report (January 1994). Well defined nanometric gold clusters (in the range 50-400A) were prepared and characterized using the citrate/PVP technique. For details see 7th Interim Report (October 1993). Nonlinear Optical Measurements Ultrashort pulse techniques were developed to study the optical nonlinearity of metal particles down to the femtosecond time domain. In the course of the work the following general observations were made. The nonlinearity is indeed faster than any pulse applicable, i.e. rises and relaxes below 20fs. Contrary to previous theories by Flytzanis et al., the nonlinearity is not size dependent, but scales with the square of the absorption efficient in agreement with a hot electron origin of the effect. (jg)

Descriptors :   *METALS, *NONLINEAR OPTICS, *CLUSTERING, OPTICAL PROPERTIES, POLYMERS, SYNTHESIS(CHEMISTRY), ORGANOMETALLIC COMPOUNDS, GRAPHITE, FULLERENES, NONLINEAR SYSTEMS, PARTICLES, PULSES, HEATING, ABSORPTION, GREAT BRITAIN.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE