Scattering from surfaces

Lykke K R and Kay B D 1990 State-to-state inelastic and reactive molecular beam scattering from surfaces Laser Photoionization and Desorption Surface Analysis Techniquesvo 1208, ed N S Nogar (Bellingham, WA SPIE) p 1218... 

While for a given surface the incident and scattered molecules have different energies (unless ac = 0), the molecule scattered from surface 1 is the molecule that is incident for surface 2. That is, since there are no gas-gas collisions when the molecule travels between the two surfaces, there is no mechanism to change the energy that it has when it leaves surface 1. Likewise, the energy of the molecules scattered from surface 2 is the same as the energy of those molecules incident upon surface 1. Thus, the temperatures are related by... 

Over 97% of the ions in a beam can be channeled in a crystal. This figure can be achieved for a well-collimated beam of MeV light ions, for which dmin is of order 0.1 A, directed along a low-index direction onto a single crystal sample. Typically, the sample is mounted on a goniometer which allows different low-index directions to be brought parallel to the beam during an experiment. The 2 or 3% of nonchanneled ions are those that hit the ends of the atomic rows at the surface or are scattered from surface disorder. 

Gerber, R.B., Kosloff, R., and Berman, M. (1986). Time-dependent wavepacket calculations of molecular scattering from surfaces, Computer Physics Reports 5, 59-114. 

In addition to imaging surfaces to study their morphology, electron beams can also be used to analyze surface structure by monitoring their scattering from surface layers on, or of monocrystals. To that end, the energy of the electrons must be kept low (10-300 eV) to suppress penetration into the solid. Hence the... 

W.A. Steele. The Interaction of Gases with Solid Surfaces, Pergamon Press (1974). (Thermodynamical and statistical theories for gas adsorption, molecular beam scattering from surfaces.)... 

E. Hulpke, ed. Helium Atom Scattering from Surfaces Springer Series in Surface Science, ed. Vol. 27. 1992, Springer Berlin. 

The effort that leads to optimization of the particle morphology is largely one of trial and error, and there is no simple means to describe the distribution of components within individual particulates. Clearly, if the majority of an active component (API) is in the interior of a particle, then the dissolution or release characteristics are likely to differ from particles where the API is predominantly on the surface. The surface distribution of proteins and polymers within spray-dried particles has been studied using electron spectroscopy for chemical analysis that involves analyzing the energy signature of electrons scattered from surfaces while being bombarded by x-rays [11,28-31], Conclusions can then be drawn... 

Applications of these tunable VUV sources continue to be mostly in the detection of atoms and small molecules by laser-induced fluorescence in molecular beam scattering studies. Of particular importance has been the improved intensities available from Mg vapor, so that it will be possible, for example, to study the internal energy distributions in CO molecules following scattering from surfaces. This capability for both very sensitive and state-selective detection of small molecules will lead to important advances in our understanding of molecular interactions at surfaces. 

E. Hulpke, editor. Helium Atom Scattering from Surfaces. Springer Series in Surface Sciences, Volume 27. Springer-Verlag, Berlin, 1992. 

G. Videen, Polarized light scattering from surface contaminants, Opt. Comm. 143, 173-178 (1997). 

Jardine, A., Ellis, J., Allison, W. Quasi-elastic helium-atom scattering from surfaces experiment and interpretation, J. Phys. Condens. Matter 2002,14,6173. 

B. Pettinger, X. Bao, I.C. Wilcock, M. Muhler, and G. Ertl, Surface-Enhanced Raman-Scattering From Surface and Subsurface Oxygen Species at Microscopically Well-Defined Ag Surfaces, Phys. Rev. Lett. 72, 1561 (1994)... 

Sandercock, J.R. Light scattering from surface acoustic phonons in metals and semiconductors. Solid State Comm. 1978, 26. 547. 

Secondary electrons 5eV Loosely bound electrons scattered from surface Main signal for Image formation... 

Further support on the role of hybridization of the noble atom orbitals with the substrate electronic states have been obtained from the ejqterimental evidence of anticorragation effects in He vs. Ne scattering from surfaces [93R] and related density functional calculations [84A, 96P]. Furthermore, intrinsic surface electronic states have been suggested to play an important role in the binding of the noble gases on metals affecting both V s and V a [96B]. 

Bouchiat, M.A. and Meunier, J., Light scattering from surface waves on carbon dioxide near its critical point, J. Physique, Colloque Cl, Suppl. no. 2-3,33, Cl-141,1972. 

New Techniques Surface X-ray diffraction is now a well-established technique for probing the atomic structure at the electrochemical interface and, since the first in situ synchrotron X-ray study in 1988 [6], several groups have used the technique to probe a variety of electrochemical systems. Most analysis has followed the methodology outlined in Sects. 4.1.2.1.1 to 4.1.2.1.3, whereby structural information at a fixed electrode potential is obtained by detailed measurement of the scattering from surface structures and modeling of the CTR profiles. In this section, a couple of recent applications of X-ray scattering are described that are particularly useful in studies of the electrochemical interface. 

Fig. 2.23. Energy spectrum of ions scattered from surface atoms full curve) and from atoms present in successive layers dashed curve)...

The time, T2, Includes contributions from all dephasing phenomena such as elastic scattering from surfaces, from impurities, from imperfections, and from electronic carriers, etc., and also includes phononr-phonon scattering which leads to phonon population decay. The population decay time is conventionally referred to as Tj. Since T2 contains Tj it follows that T2 Tp... 

R. Viswanathan. S. Shi, E. Vilallonga and H. Rabitz. Sensitivity analysis of the potential for elastic gas-solid scattering from surface defects. Surf. Sci. (1991), in press. 

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