Scattering of linear molecules from solid surfaces

• Published in: Surface science 1981-10, Vol.110 (2), p.270-286
• Main Author: Asada, Hiromu
• Format: Article
• Language: English
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(81)90638-5

Scattering of linear molecules, which are internally deactivated initially, from solid surfaces is investigated classical mechanically. The solid is modeled with a three-dimensional isotropic Debye solid whose surface is essentially flat but thermally roughened by lattice vibration, and the molecule is described as a rigid body, which interacts with the solid via an exponential potential wall and a stationary attractive potential well. A variation in the interaction energy due to thermal roughening of the surface and due to nonsphericity of the molecule being regarded as perturbations on the system, a second order perturbation theory is developed to construct a Gaussian velocity distribution function of molecules scattered off the exponential wall and still moving inside the potential well. Among the molecules in the distribution, those with sufficient energy to escape from the potential well are regarded as being scattered into the free space. This model shows that the major differences between the scattering of monatomic molecules and that of linear ones result from less normal momentum transfer to the linear molecules than to the monatomic ones.