Applications of X-ray Diffraction in the Imaging Industry

X-ray diffraction characterization of materials used in traditional silver halide and digital semiconductor photographic systems is described. Silver halide grains precipitated as multicomponent AgBr1-xIx phases were found to be comprised of a core with three shells. The composition of the core and shells was determined using lattice constant measurements. Nanocomposites for photographic antistatic applications were generated by mixing an aqueous dispersion of a 2:1 layered clay with a polyester ionomer. The extent of polymer intercalation and disorder of the clay platelets was monitored by observing any change in the clay (001) basal plane d-spacing as a function of composition. Silicon wafers used as substrates for digital photographic sensors were evaluated for the effect of depositing an epitaxial silicon layer on the wafer. A reciprocal space map constructed from high-resolution triple axis diffraction scans revealed that there was no detectable strain and the bulk silicon was comprised of a very smooth surface and few bulk-crystal defects. A gallium arsenide wafer with an epitaxial aluminum gallium arsenide film, utilized for light-emitting diodes, was also analyzed using a triple-axis diffractometer. The reciprocal space map revealed that the gallium arsenide substrate has a tilt boundary, and there is a compositional grading with a large population of dislocations.