Partial funding is provided for the acquisition of a high resolution powder x-ray diffractometer to support basic research in materials chemistry by faculty in the Chemistry, Chemical Engineering, and Clay Mineralogy programs at Pennsylvania State University. The primary users will be eight faculty and 43 graduate students, postdoctoral fellows, undergraduates, and research associates. The instrument will have special capabilities for low-angle x- ray diffraction of materials with large unit cell dimensions; and for thin films of layered materials. It will have a Peltier detector for increased sensitivity, a glancing angle attachment for the study of nanocomposite materials containing small crystallites in polymer matrices, and modern software for library searching of known phases, indexing, peak fitting, and profile refinement of crystal structures. The x-ray diffraction equipment currently available at the University is not adequate for many of the proposed experiments, e.g., studies of metal-organic thin films, polymer multilayer structures, intercalated clays with large interlayer spacings, new mesoporous molecular sieves, and ab initio solution of crystal structures from powder x-ray diffraction data. This equipment will be dedicated to non-routine research problems. Routine qualitative phase identification in polycrystalline samples will continue to be conducted on the existing diffractometers. A primary objective in the study of new solid state compounds and composite materials, regardless of their ultimate application, is the determination of the relationship between physical properties and the structure and/or surface composition. X-ray diffraction is the most generally applicable and powerful technique for this purpose.
