Studies of Electron-Irradiation-Induced Changes to Monomolecular Structure

Abstract

The study of irradiation-induced changes to molecular structure has been pursued by radiation physicists and chemists for many decades. In recent years with the advent of techniques to probe the structure of molecules adsorbed on surfaces, there is a great need to quantitatively understand the changes induced in such structures due to the action of the probe. For example, in atomic resolution electron microscopy,⁽¹⁾ the deleterious action of energetic electrons needs to be understood and eventually minimized; in electron spectroscopy⁽²⁾ of adsorbed molecular films, the degrading action of energetic electrons on the energy-loss spectrum needs to be quantified, in order to completely characterize the spectra; in electron diffraction⁽³⁾ studies of molecular crystals, the deterioration of intensity due to structure changes needs to be convolved with the true diffraction pattern; in Auger electron spectroscopy,⁽⁴⁾ the sensitivity of the spectrum to small changes in submonolayer quantities of the adsorbed molecules needs to be understood. In brief, the action of the probe on a monolayer molecular specimen needs to be understood and quantified. It is hoped that such fundamental understanding will lead to “tailoring” of molecules that are more resistant (or more sensitive) to radiation action, thereby opening new avenues for applications of radiation-induced adsorbed molecular chemistry.