A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Atom Scattering from a Markovian bcc(001) Surface
Abstract Atom scattering from a disordered surface has attracted attention in recent years /1–10/ as a tool to study the roughening transition: in particular the declining intensity of the Bragg peaks /1, 2/ and the shape and width of the incoherent scattering /2–10/ have been considered, both experimentally and theoretically. The situation is simpler above the transition (on the “rough” side) where there is no coherent scattering, and the logarithmic dependence of the mean square height difference (mshd) leads to a power-law incoherent peak shape /3–9/. The situation below the transition (on the “smooth” side) has been less extensively studied. Very recently, however, two of us /10/ have presented a study of scattering in this range. The Markovian approximation, used some years ago to describe the surface on the “rough” side /2/, was extended to the “smooth” side. A justification for this is that it affords a complete description of the stochastic behaviour of a surface, which is necessary for computing the atom scattering intensity distribution. If, instead of a Markovian approximation, an exact mshd was used, and then a Gaussian approximation applied to obtain the joint probability distribution, as is often done, the result would be even worse (since the distribution is very far from Gaussian) /10/. Moreover a Markovian approximation is more justified, on the whole, on the “smooth” than on the “rough” side of the transition (where it conflicts with the known logarithmic behaviour).
Atom Scattering from a Markovian bcc(001) Surface
Abstract Atom scattering from a disordered surface has attracted attention in recent years /1–10/ as a tool to study the roughening transition: in particular the declining intensity of the Bragg peaks /1, 2/ and the shape and width of the incoherent scattering /2–10/ have been considered, both experimentally and theoretically. The situation is simpler above the transition (on the “rough” side) where there is no coherent scattering, and the logarithmic dependence of the mean square height difference (mshd) leads to a power-law incoherent peak shape /3–9/. The situation below the transition (on the “smooth” side) has been less extensively studied. Very recently, however, two of us /10/ have presented a study of scattering in this range. The Markovian approximation, used some years ago to describe the surface on the “rough” side /2/, was extended to the “smooth” side. A justification for this is that it affords a complete description of the stochastic behaviour of a surface, which is necessary for computing the atom scattering intensity distribution. If, instead of a Markovian approximation, an exact mshd was used, and then a Gaussian approximation applied to obtain the joint probability distribution, as is often done, the result would be even worse (since the distribution is very far from Gaussian) /10/. Moreover a Markovian approximation is more justified, on the whole, on the “smooth” than on the “rough” side of the transition (where it conflicts with the known logarithmic behaviour).
Atom Scattering from a Markovian bcc(001) Surface
Levi, A. C. (author) / Spadacini, R. (author) / Tommei, G. E. (author)
1988-01-01
5 pages
Article/Chapter (Book)
Electronic Resource
English
Metastable helium atom scattering from Ni(110) surface
| British Library Online Contents | 2001
Theoretical Aspects of Atom-Surface Scattering
| Springer Verlag | 1992
Helium Atom Scattering from Surfaces
| TIBKAT | 1992
Semiclassical treatment of atom-surface scattering: He-Cu(001) collisions
| British Library Online Contents | 1999