George L. Clark X-Ray Facility

The X-ray facility performs a wide variety of experiments including small and wide angle X-ray scattering, in addition to powder, fiber, and single crystal X-ray diffraction. This facility helps maintain structural database systems that provide electronic search, retrieval, analysis, data, and graphics for inorganic, organic, and macromolecular structures. Facility personnel help investigators correlate X-ray diffraction results with other single crystal and bulk sample experiments including laser, EPR, NMR, and microwave. The staff also offers instruction covering X-ray diffraction experiments from design and data collection to analysis and presentation of results. Experimental data for research groups is routinely provided in less than one week. Alternatively, faculty, staff, students, and visitors are welcome to use facility equipment to collect their own data.

The George L. Clark X-ray Facility is the X-ray diffraction and scattering component of the Center for Complex Structures. The laboratory maintains several experimental systems.

Experimental Systems

• The first is a Bruker Molecular Analysis Research Tool (SMART) equipped with a 3-circle platform diffractometer and charge-coupled device (CCD) area detector. This system is used primarily for low temperature, single crystal diffraction, and can effectively obtain high quality data from crystals with minimal volume or multiple domains.
• The second and newest system is a Bruker X8ApexII (APEX). It is equipped with a four-circle kappa-axis diffractometer and motorized ApexII CCD detector. This state-of-the-art multipurpose system is primarily used for variable temperature, single crystal experiments on samples with a minimum dimension of 0.01mm. The system is also available for wide-angle, powder, film, and fiber X-ray diffraction experiments on samples ranging from minerals to macromolecules.
• The third system is a Bruker General Area Detector Diffraction System (GADDS) equipped with a four-circle diffractometer and HiStar multiwire area detector. This multipurpose system is used for wide-angle, powder, film, and fiber X-ray diffraction, as well as variable temperature, single crystal experiments on samples ranging from minerals to macromolecules.
• The fourth system is a Bruker Small Angle X-ray Scattering (SAXS) system equipped with an automated Anton Paar sample chamber and HiStar multiwire area detector. This multipurpose system is used to help characterize materials with extremely long molecular repeat spacing.

Additional systems are available for designer experiments that require unusual physical environments or peripherals. These user-designed systems perform very specialized experiments, like measuring molecular geometry as a function of temperature, pressure, or fluid properties.

Separately and in various combinations these systems have inspired a new generation of questions about molecular geometry in solids, liquid crystals, colloids, and solutions. Scientists in disciplines ranging from physics to food science are taking advantage of the expanded spectrum of X-ray diffraction and scattering experiments currently available.