Hermetic sample enclosure for simultaneous differential scanning calorimetry/synchrotron powder x-ray diffraction

A hermetic sample enclosure for performing simultaneous differential scanning calorimetry/synchrotron powder x-ray diffraction was designed, and a prototype was fabricated. The enclosure design is based upon a Perkin-Elmer DSC-2C measuring head with modifications allowing an unobstructed x-ray beam access to the sample in a controlled-atmosphere environment. The modifications to the measuring head base are limited to exposing the sample and reference platinum cups and providing a mating surface for the head cover. A completely new head cover, featuring semicylindrical beryllium x-ray windows, is hermetically attached to the base. A new graphite sample pan, addressing the conflicting requirements of differential scanning calorimetry and powder x-ray diffraction, was designed, and multiple pans were fabricated. An alternative temperature measurement and control system was developed and assembled. The complete system was tested in three experiments. No problems were encountered with diffraction data acquisition and temperature control, however, calorimetric resolution was mediocre. The alternative temperature measurement and control system will have to be optimized. (C) 1999 American Institute of Physics. [S0034-6748(99)03705-3].