Micro-diffraction based crystallography is essential to materials design and process understanding in key industrial applications, such as micro-electronics, superconductivity, solar energy, structural composites and metal forming. The scanning electron microscope (SEM) has the potential for providing high spatial resolution crystallographic information, but its applicability is severely limited by the low sensitivity of existing techniques. The current methodology cannot be easily used for dose sensitive materials, electrical nonconductors and samples with even small amounts of surface damage. The difficulty of obtaining micro- diffraction data is a major drawback in the SEM, which otherwise is very useful in obtaining high resolution topographical and compositional information and usually requires minimal specimen preparation. This Phase I program will determine the feasibility of employing an energy filtering detector with high gain to increase the sensitivity of micro-diffraction in the SEM. The filter will be applied to backscattered electron patterns that can provide crystallographic information at very high spatial resolution. This study will require an amplifying element that is sensitive to low energy electrons, such as a microchannel plate. The research will test the overall feasibility of this approach as well as the specific issues of dynamic range and noise level. Exploitation of the proposed research would improve the competitive position of domestic industries by enhancing their capability to identify components and define aggregate properties related to advanced materials and processes. In addition it would extend the functionality of a large existing base of scanning microscopes used in academic and industrial research.
