Equipment: MRI: Track 1 Acquisition of a multi-modal x-ray diffraction and scattering instrument

The ability to describe the structure of a material – from the arrangement of atoms to the roughness of a surface – is foundational to the field of materials science and engineering. Determining how material structure changes during use or due to interactions with the environment is critical to understanding and addressing challenges as diverse as climate change, clean and efficient energy production and utilization, and disease detection.

X-ray diffraction and scattering (XRD/S) techniques are uniquely capable of probing a broad range of structural features. The X-ray analysis system acquired in this project can be easily reconfigured to perform several complementary measurements and identify critical structural features responsible for a material’s behavior and functionality. Examples of the research enabled by this XRD/S instrument include improving the performance of materials used in batteries and ultra-thin electronic devices; designing new environmentally friendly biopolymers; developing inexpensive sensors to detect viruses and antibodies; discovering new alloys for light-weight automobiles and aircraft; and identifying and mitigating environmental contaminants in the water and air.

At least 25 research groups spanning 8 disciplines at 5 universities plan to employ the instrument in their research. Additionally, the instrument will be a vital resource for training the next generation of scientists and engineers in a diverse set of measurement techniques. The instrument will be used by undergraduate and graduate students in a hands-on materials characterization course sequence, as well as in technical skills workshops that will be open to internal and external users.

The multi-modal XRD/S instrument will enable researchers to probe materials structure in the following ways: • X-ray diffraction (XRD): XRD provides phase identification, lattice parameters, and domain size.

• Small- and wide-angle X-ray scattering (SAXS/WAXS): SAXS provides information on size, shape, ordering, and self-similarity of materials on the 1-100 nm length scale while WAXS (often simultaneously) provides phase identification and an assessment of crystallinity. • X-ray reflectometry (XRR): XRR evaluates roughness and film thickness on flat surfaces.

• Grazing incidence X-ray diffraction (GI-XRD): GI-XRD is a surface-sensitive XRD measurement, enabling determination of thin film strain, disruption of surface crystallinity, and surface precipitates.

These modes are enhanced by a unique microfocus X-ray source for precisely collimating the incident X-ray beam, which maximizes the beam intensity and significantly reduces data collection times relative to conventional sealed tube sources. Accessories include a high-resolution translation stage, a battery cell and potentiostat, and an atmosphere-controlled heating/cooling stage, which enable high-throughput, in situ, and operando observations of dynamic phenomena crucial to understanding and manipulating materials behavior.

These capabilities will be brought to bear on a wide range of materials research problems, including energy conversion and storage, geological and environmental systems, bio-derived materials and other polymers, and accelerated materials discovery and design.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.