Acquisition of an X-Ray CCD Detector System for Materials Research at Advanced Photon Source

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9802643ChenThis award provides partial support for the acquisition of an analytical x-ray CCD system, complete with a 2K x 2K pixel CCD camera, a 3-axis goniometer, a computer workstation and a comprehensive software package for data acquisition and crystal structure determination. This CCD system will be used at the UNICAT undulator beam line at the Advanced Photon Source (APS), Argonne National Laboratory, as a common facility available to both UNICAT members and Independent Investigators. Training for the use of this CCD system will be carried out by UNICAT scientific staff via a sector-specific training program already in existence as a part of the UNICAT management plan that was approved by APS.UNICAT is a University-National Laboratory-Industry Collaborative Access Team including the University of Illinois at Urbana-Champaign (UIUC), the Oak Ridge National Laboratory (ORNL), the National Institute of Standards and Technology (NIST) and the UOP Research and Development. The UNICAT consortium is presently funded to construct one sector, i.e. two beamlines, at the Advanced Photon Source. The Bending Magnet beamline will have experimental capablilities for x-ray adsorption spectroscopy, for x-ray topography imaging and for general purpose x-ray diffraction. The UNICAT Insertion Device beamline will have two experimental stations: a high-resolution x-ray diffractometer and a dedicated surface/interface diffractometer. The UNICAT Insertionn Device beamline and its two experimental stations have been in preliminary commissioning operation since August 1997; the anticipated date for a full operation is December 1998.The x-ray CCD system will be principally utilized by UIUC and UOP scientists to carry out scientific projects in three main areas: (1) microcrystal diffraction for structure determination, (2) small-angle x-ray scattering, and (3) time-resolved surface/interface scattering. For microcrystal diffraction, projects encompass structure determination from micron-sized single crystals such as zeolites and single fiber filaments. Small-angle x-ray scattering portion of the work includes transmission and grazing-incidence geometry to study problems such as crystallization kinetics measurements of zeolites from solutions, 2-dimensional epitaxial nucleation and growth mechanism based on self-affine fractal geometry and scaling concept of MOCVD-derived oxide thin films, etc. The third research area is in time-resolved surface/interface scattering for which kinetic roughening, interface strain and growth, and evolution of surface/thin film morphology will be investigated using surface-sensitive scattering techniques. All proposed scientific programs represent topics of scientific and technological challenges which can greatly benefit from the use of a 2-d CCD detector in conjunction with the high-brilliance synchrotron radiation produced by the undulator insertion devices of the third-generation source at APS.%%%***