The Menzel Comer Redhead (MGR) model for ESD ( Details )
One of the earliest and general models to explain ESD from surfaces.
Fig 1 shows the desorption of adsorbed species as an ion.
Fig 2 shows the neutral desorption.
An Isolated Event for Electron-Adsorbate Collision ( Details )
It has been observed that the electron-adsorbate scattering is an isolated event. This comes from the fact that the probability of an adparticle interacting simultaneously with more than one primary electron is small. This preliminary consideration then set the stage for a description of ESD events in terms of isolated electron adsorbate interactions where electronic energy transfer plays the predominant role.
Electronic excitation vs direct momentum transference ( Details )
The energy transfer for electron atomic hydrogen collisions is less than 0.5 eV. However, ESD experiments often observe desorbing molccules, ions and molccular fragments with kinetic energies in the range from 2-10 eV. This indicates that direct momentum transfer is not usually dominant in electron adsorbate collisions, and that electronic energy transfer must be considered.
The Menzel Comer Redhead (MGR) model for ESD ( Details )
One of the earliest and general models to explain ESD from surfaces.
Fig 1 shows the desorption of adsorbed species as an ion.
Fig 2 shows the neutral desorption.
Antoniewicz model for ESD ( Details )
A modification of the original MGR model.
Successful in describing ESD from physisorbed layers.
Fig.1 illustrates this proposed sequence leading to neutral particle desorption. (The moving point simply shows the changing potential of desorbing particle)
The direction in which the ions are emitted is used to determine bond directionality. There are two effects which have major influence on ESDIAD:
The image force
neutralisation.