Author: J. E. Demuth
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
High resolution electron energy loss (EELS), UV photoemission, (UPS), low energy electron diffraction (LEED), Auger electron, and thermal desorption spectroscopic techniques have been applied to characterize the bonding, molecular orientation and vibrations of pyridine and benzene on clean Ag(111). These results are used to interpret the surface enhanced Raman spectra of these molecules adsorbed on a clean, well-defined single crystal Ag(111) surface containing a smooth periodic modulation (1 micron wavelength, approx. 500 A amplitude) which permits optical coupling to surface plasmons-polaritons. We observe enhanced Raman scattering (RS) for chemisorbed species only when we are at appropriate incidence angles so as to excite surface plasmons. Coverage-dependent RS studies indicate a long-range field enhancement of approx. 100 for physisorbed layers and a mode-selective, short-range enhancement of approx 10,000 for the symmetric ring breathing mode of pyridine. This short-range enhancement only occurs for pyridine coverages slightly above 3 x 10 to the 14th power molecules/sq cm where changes in the UPS spectra and our UPS derived uptake-rates are also observed. Similar coverage-dependent effects are also observed in UPS and EELS for chemisorbed pyridine on the ideal Ag(111) surface. These as well as LEED results showing the modulated surface to be predominately (approx. 90%) single crystal Ag(111), encourage us to directly compare the results obtained for the two surfaces.
High Resolution Electron Energy Loss and Surface Enhanced Raman Studies of Pyridine and Benzene on Ag(111).
Author: J. E. Demuth
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
High resolution electron energy loss (EELS), UV photoemission, (UPS), low energy electron diffraction (LEED), Auger electron, and thermal desorption spectroscopic techniques have been applied to characterize the bonding, molecular orientation and vibrations of pyridine and benzene on clean Ag(111). These results are used to interpret the surface enhanced Raman spectra of these molecules adsorbed on a clean, well-defined single crystal Ag(111) surface containing a smooth periodic modulation (1 micron wavelength, approx. 500 A amplitude) which permits optical coupling to surface plasmons-polaritons. We observe enhanced Raman scattering (RS) for chemisorbed species only when we are at appropriate incidence angles so as to excite surface plasmons. Coverage-dependent RS studies indicate a long-range field enhancement of approx. 100 for physisorbed layers and a mode-selective, short-range enhancement of approx 10,000 for the symmetric ring breathing mode of pyridine. This short-range enhancement only occurs for pyridine coverages slightly above 3 x 10 to the 14th power molecules/sq cm where changes in the UPS spectra and our UPS derived uptake-rates are also observed. Similar coverage-dependent effects are also observed in UPS and EELS for chemisorbed pyridine on the ideal Ag(111) surface. These as well as LEED results showing the modulated surface to be predominately (approx. 90%) single crystal Ag(111), encourage us to directly compare the results obtained for the two surfaces.
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
High resolution electron energy loss (EELS), UV photoemission, (UPS), low energy electron diffraction (LEED), Auger electron, and thermal desorption spectroscopic techniques have been applied to characterize the bonding, molecular orientation and vibrations of pyridine and benzene on clean Ag(111). These results are used to interpret the surface enhanced Raman spectra of these molecules adsorbed on a clean, well-defined single crystal Ag(111) surface containing a smooth periodic modulation (1 micron wavelength, approx. 500 A amplitude) which permits optical coupling to surface plasmons-polaritons. We observe enhanced Raman scattering (RS) for chemisorbed species only when we are at appropriate incidence angles so as to excite surface plasmons. Coverage-dependent RS studies indicate a long-range field enhancement of approx. 100 for physisorbed layers and a mode-selective, short-range enhancement of approx 10,000 for the symmetric ring breathing mode of pyridine. This short-range enhancement only occurs for pyridine coverages slightly above 3 x 10 to the 14th power molecules/sq cm where changes in the UPS spectra and our UPS derived uptake-rates are also observed. Similar coverage-dependent effects are also observed in UPS and EELS for chemisorbed pyridine on the ideal Ag(111) surface. These as well as LEED results showing the modulated surface to be predominately (approx. 90%) single crystal Ag(111), encourage us to directly compare the results obtained for the two surfaces.
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 788
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 788
Book Description
Surface Enhanced Raman Vibrational Studies at Solid Gas Interfaces
Author: I. Pockrand
Publisher: Springer
ISBN: 3540389520
Category : Science
Languages : en
Pages : 172
Book Description
Publisher: Springer
ISBN: 3540389520
Category : Science
Languages : en
Pages : 172
Book Description
Vibrations at Surfaces
Author: R. Caudano
Publisher: Springer Science & Business Media
ISBN: 1468440586
Category : Science
Languages : en
Pages : 570
Book Description
This volume contains most of the invited and contributed papers presented at the second international conference devoted to the general topic "Vibrations at Surfaces" and which took place from 10 to 12 September 1980 at the Facu1tes Notre-Dame de 1a Paix in Namur, Belgium. The conference was organized to review the large amount of information gathered in this field over the late seventies as a result of th~ rapid improvements and dissemination of surface spectroscopic technique such a electron energy loss, infrared and Raman surface spectroscopies. Much time was devoted to Raman spectroscopy of adsorbed mo1e 'cu1es. After several years of vivid debate over the causes of the observed large enhancement of Raman cross section, a clearer pic ture emerges from the papers presented here: the actual value of the enhancement factor does depend in a complicated manner on long range surface roughness, atomic-scale roughness and the dielectric properties of the substrate as well as on the electronic structure of the molecule in its adsorbed state. Less controversial are the results obtained with electron energy loss spectroscopy (EELS) and several sessions of the con ference were devoted to the approach. As witnessed by the growing number of laboratories using the technique, EELS is now a mature spectroscopic tool for the characterization and analysis of the chemisorption bond.
Publisher: Springer Science & Business Media
ISBN: 1468440586
Category : Science
Languages : en
Pages : 570
Book Description
This volume contains most of the invited and contributed papers presented at the second international conference devoted to the general topic "Vibrations at Surfaces" and which took place from 10 to 12 September 1980 at the Facu1tes Notre-Dame de 1a Paix in Namur, Belgium. The conference was organized to review the large amount of information gathered in this field over the late seventies as a result of th~ rapid improvements and dissemination of surface spectroscopic technique such a electron energy loss, infrared and Raman surface spectroscopies. Much time was devoted to Raman spectroscopy of adsorbed mo1e 'cu1es. After several years of vivid debate over the causes of the observed large enhancement of Raman cross section, a clearer pic ture emerges from the papers presented here: the actual value of the enhancement factor does depend in a complicated manner on long range surface roughness, atomic-scale roughness and the dielectric properties of the substrate as well as on the electronic structure of the molecule in its adsorbed state. Less controversial are the results obtained with electron energy loss spectroscopy (EELS) and several sessions of the con ference were devoted to the approach. As witnessed by the growing number of laboratories using the technique, EELS is now a mature spectroscopic tool for the characterization and analysis of the chemisorption bond.
Technical Abstract Bulletin
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 216
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 216
Book Description
Ultrahigh-vacuum Studies of Surface Enhanced Raman Scattering from Absorbates on Modulated Silver Surfaces
Author: Pia Naoko Sanda
Publisher:
ISBN:
Category : Raman effect, Surface enhanced
Languages : en
Pages : 300
Book Description
Publisher:
ISBN:
Category : Raman effect, Surface enhanced
Languages : en
Pages : 300
Book Description
Government Reports Announcements & Index
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 792
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 792
Book Description
Physics Briefs
Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 914
Book Description
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 914
Book Description
Government Reports Annual Index
Author:
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1320
Book Description
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1320
Book Description
Selected Papers on Surface-enhanced Raman Scattering
Author: Milton Kerker
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 728
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 728
Book Description