1. High-energy Electron Beam Stimulated Chemical Reaction 0603993 An external electric field induced chemical reactions, known as electrochemical reactions, as in rechargeable batteries, are redox reactions, involving oxidation and reduction process. The dynamics of high-energy electron beam stimulated reactions, however, are quite different. The interactions of incident high-energy electrons with atoms and atom electrons are more complicated, involving direct transfer of kinetic energy and radiolysis. Very little is known about the process of reaction at atomic scale. In order to observe the dynamical process of electron beam stimulated reactions, we have developed techniques utilizing time-resolved electron energy-loss spectroscopy (EELS) in a transmission electron microscope. So far successes of this program include the direct observation of the high-energy electron beam stimulated transition from Al(OH)3 to  -type amorphous Al2O3 (see figure). First, the H atoms are removed quickly by knock-on interaction, leaving O in surplus (Al(OH)3  AlO3 +3H  ). The O2 then quickly forms and the layered Al(OH)3 structure collapses (AlO3   -Al2O3 +O2  ). The newly formed structure contains tetrahedrally coordinated Al, as in  - Al2O3. This knowledge also aids the proper characterization of H- containing materials.

2. High-energy Electron Beam Stimulated Chemical Reaction 0603993

3. Broad impacts: This program uniquely combines the electron energy-loss spectroscopy and electron irradiation techniques. It offers the realistic prospect of understanding and manipulating atomic structures by new means in order to obtain wanted novel properties.