W0059

Rapid Combinatorial Screening by Transmission XRD. Bob B. He, Uwe Preckwinkel and Kingsley L. Smith, Bruker Advanced X-ray Solutions, Madison, WI, USA.

In many combinatorial screening applications, such as polymorphism studies in pharmaceutical chemistry and catalysis development in the oil industry, a typical 2_ measuring range is from 2 to 60_. It is necessary to run the combinatorial XRD screening in transmission mode in order to avoid the defocusing effect associated with reflection mode diffraction. In the transmission mode X-ray diffraction measurement, the incident beam is typically perpendicular to the sample so the irradiated area on the specimen is limited to a size comparable to the X-ray beam size, allowing the X-ray beam concentrated to the intended measuring area. In combinatorial screening applications, sample cells are located close to each other. Therefore, the transmission mode diffraction can also avoid cross contamination between adjacent cells in material library. A two-dimensional X-ray diffraction system designed for high throughput combinatorial screening in transmission mode is introduced in the presentation.