Within the first week of installation, Oregon State’s new diffractometer, an instrument that uses X-rays and a detector to produce images of tiny crystals, produced enough data about eight new structures, all fit for publication in peer-reviewed science journals. It is not only fast — “What used to take two hours now takes eight minutes!” exclaims chemist May Nyman — it is capable of analyzing smaller crystals, has fewer runtime errors, and has two X-rays to pick from to optimize imaging for different crystals.
Why is taking X-rays of tiny crystals such a big deal? It is a window into the unknown, and not just for seasoned scientists. Students who make new crystal compounds can analyze them with the diffractometer and be “the first person in the world to peer inside that bit of chemical knowledge,” according to May Nyman.
“What used to take two hours now takes eight minutes!”
The new diffractometer was funded through the generosity of the Murdock Charitable Trust, which supports scientific and engineering research in the Pacific Northwest, and matched by private support from the College of Science Renaissance Fund and other donor-supported funds from the colleges of Agricultural Sciences, Engineering and Pharmacy. A large rectangular machine, about 6 feet tall and 4 feet wide and deep, the new diffractometer is located in the Agricultural Life Science Building. Most of its bulk is to allow for a lead-glass enclosure around all of the working parts to protect users from the X-rays, which are similar to dental or medical X-rays.
Scientists use X-ray diffraction to understand the exact arrangement of atoms inside new materials discovered by synthesis or extraction from a natural material, including biomaterials such as proteins, DNA, new pharmaceuticals and inorganic materials, such as those used for energy or environmental applications. Knowing the arrangement of atoms in a material tells us how it is able to cure disease, for example, or to harvest energy from the sun.
“In order for this technique to work,” explains Nyman, “the crystal must be close to perfect and pure; not cracked, not stuck to another crystal, not covered with any debris. This means we are usually analyzing very tiny crystals. As an example, a crystal the size of a grain of rice is considered very large, sometimes too big because the X-rays cannot get through so efficiently. Sometimes we analyze crystals so tiny that you can hardly see them with your naked eyes!”
Once hundreds to thousands of images are produced, the process of solving the structure – correctly interpreting the images – begins. Nyman describes this process as “sometimes frustrating” but “really fun,” like a puzzle. “It involves 3D visualization software, and you win the game by assigning all of your atoms correctly and achieving as low an ‘R-value’ as possible (a measure of the correlation between the model and the diffraction data).”
Students trained in all of the steps of diffraction data gathering and interpreting have a valuable skill set that not only yields rapid knowledge to advance research, but also can translate to marketable skills in a wide range of careers in chemistry research from academia to government to industry.
The new diffractometer’s ability to analyze smaller crystals than any other diffractometer in Oregon has already attracted scientists from the University of Oregon and interest from other regional universities and industries who would like to take advantage of this fantastic capability. And anyone who grows single crystals on campus will use the diffractometer, including students, postdocs and faculty.
One of the most exciting structures from the new diffractometer is a “cluster of clusters,” containing both uranium and ytterbium, one of the rare earth elements. Both of these elements, from the bottom of the periodic table, still hold many mysteries for scientists. According to Nyman, these more rare earth elements, combined with metals higher up on the periodic table known as transition metals, have found use in wind turbines and magnetic brakes for hybrid materials. They can also be used in quantum computing. “Combining the rare earths with uranium has rarely been achieved and will open up a whole new level of understanding of how the electrons in these elements behave,” says Nyman. “We have never seen before this hierarchical arrangement of clusters that assemble into other clusters. It is beautiful and fascinating!”
The new diffractometer is expected to open up new avenues of research on campus and across Oregon.