Instrumentation
The Molecular Structure Facility maintains three single-crystal diffractometers, a powder diffractometer in Bragg-Brenatano geometry, and a point-source, 2D-detector powder diffractometer.
The single crystal instruments consist of a Bruker Venture Photon-III instrument with a copper Diamond microfocus X-ray source. A Bruker Quest Photon-III instrument with a molybdenum microfocus X-ray source and a Bruker D8 APEX-II equipped with an Mo sealed-tube source and a Cu microfocus source.
The Venture and Quest instruments have a 4-circle Kappa geometry and the D8 instrument has a 3-circle fixed-chi geometry.
Nearly all experiments in the facility are performed at cryogenic temperatures,120 K for most samples, using a cooled nitrogen gas stream. However, nearly any temperature from 100 to 400 K can be reached.
The powder diffractometer provides a fast, efficient means to verify the chemical phases of materials and also to determine if results from single-crystal analyses are consistent with the composition of the bulk solids.
A necessary prerequisite to data collection is crystal selection. Because the crystals are small, (0.1 x 0.1 x 0.1 mm), they are examined and selected using a stereomicroscope. The facility is equipped with two polarizing stereomicroscopes. Both microscopes are capable of 100 X magnification allowing for easy optical examination of samples. Both microscopes are equipped with digital cameras to allow discussion and instruction about samples.
Instrumentation in the facility is supported by NSF Award CHE-2214606.