Abstract:
With the demand for higher rates of discovery in the materials field,
characterization techniques that are capable of rapidly and reliably surveying
the characteristics of large numbers of samples are essential. A chemical
combinatorial approach using thin films can provide detailed phase diagrams
without the need to produce multiple, individual samples. This is achieved with
compositional gradients forming high-density libraries. Conventional raster
scanning of chemical or structural probes is subsequently used to interrogate
the libraries. A new, alternative approach to raster scanning is introduced to
provide a method of high-throughput data collection and analysis using an X-ray
diffraction probe. Libraries are interrogated with an extended X-ray source and
the scattering data collected using an area detector. A simple technique of
'partitioning' this scattering distribution enables determination of information
comparable to conventional raster scanned results but in a dramatically reduced
collection time. The technique has been tested using synthetic X-ray scattering
distributions and those obtained from contrived samples. In all cases, the
partitioning algorithm is shown to be robust and to provide reliable data;
discrimination along the library principal axis is shown to be similar to 500 mm
and the lattice parameter resolution to be similar to 10(-3) A angstrom mm(-1).
The limitations of the technique are discussed and future potential applications
described.
