The authors report on the optical absorption spectra of Au atoms and dimers deposited on amorphous SiO2 in size-selected fashion. Exptl. spectra were obtained by cavity ringdown spectroscopy. Issues on soft-landing, fragmentation, and thermal diffusion are discussed from the exptl. results. In parallel, cluster and periodic supercell d. functional theory (DFT) calcns. were performed to model atoms and dimers trapped on various defect sites of amorphous SiO2. Optically allowed electronic transitions were calcd., and comparisons with the exptl. spectra show that Si dangling bonds [≡Si.bul.], nonbridging O [≡Si-O.bul.], and the silanolate group [≡Si-O-] act as trapping centers for the Au particles. The results are not only important for understanding the chem. bonding of atoms and clusters on oxide surfaces, but they will also be of fundamental interest for photochem. studies of size-selected clusters on surfaces. [on SciFinder(R)]     «

The authors report on the optical absorption spectra of Au atoms and dimers deposited on amorphous SiO2 in size-selected fashion. Exptl. spectra were obtained by cavity ringdown spectroscopy. Issues on soft-landing, fragmentation, and thermal diffusion are discussed from the exptl. results. In parallel, cluster and periodic supercell d. functional theory (DFT) calcns. were performed to model atoms and dimers trapped on various defect sites of amorphous SiO2. Optically allowed electronic transiti...     »

Bond (dangling, for silicon gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements) Cluster model Electronic transition Energy level excitation Fragmentation reaction Optical properties UV and visible spectra (gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements) Trapping (silanolate centers for gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements) Diffusion (thermal gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements) gold atom dimer amorphous silica substrate optical property cavity ringdown spectroscopy gold fragmentation thermal diffusion     «

Bond (dangling, for silicon gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements) Cluster model Electronic transition Energy level excitation Fragmentation reaction Optical properties UV and visible spectra (gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements) Trapping (silanolate centers for gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavit...     »

CAN 143:484645 73-2 Optical, Electron, and Mass Spectroscopy and Other Related Properties Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Milan, Italy. Journal 1520-6106 7440-57-5 (Gold); 12187-09-6 (Gold dimer) Role: PRP (Properties) (gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements); 7631-86-9 (Silica) Role: NUU (Other use, unclassified), USES (Uses) (substrate; gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements)     «

CAN 143:484645 73-2 Optical, Electron, and Mass Spectroscopy and Other Related Properties Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Milan, Italy. Journal 1520-6106 7440-57-5 (Gold); 12187-09-6 (Gold dimer) Role: PRP (Properties) (gold atoms and dimers on amorphous SiO2: calcn. of optical properties and cavity ringdown spectroscopy measurements); 7631-86-9 (Silica) Role: NUU (Other use, unclassified), USES (Uses) (substrate; gold atoms and dimers on amorphous SiO2: c...     »