In July 2018, NSF’s ChemMatCARS hosted two graduate students under our Graduate Student Research Award at ChemMatCARS (GSRAC) program. Both took away a better sense of the opportunities and realities of x-ray science—and confirmation that they’re on the right path.
Jesse Murillo of the University of Texas at El Paso performed single-crystal diffraction on samples for his dissertation research on lanthanide-containing coordination complexes that are of interest for single-molecule magnetism. Oscar S. Hernández-Daguer, a master’s student at the University of Puerto Rico at Mayagüez, pursued an intensive orientation to x-ray physics in preparation for reorienting his Ph.D. studies from solid state physics to x-ray microscopy.
This was Murillo’s second sponsored visit doing crystallography at Sector 15. In 2017 he and his professor Skye Fortier visited for two days under our other sponsored-visit program, FaSTRAC. During that visit he learned about the GSRAC program and was immediately interested.
On this one-month visit, Murillo brought samples from his doctoral research in organometallic synthetic chemistry. “The project I brought this summer has to do with lanthanides. We’re trying to make single molecules that exhibit single-molecule magnetism, which is pretty unique in the world of inorganic chemistry. But it’s difficult, because a lot of the materials I make crystallize poorly, so I have a hard time characterizing them structurally. We do have a crystallographic lab and a diffractometer, but for most of those compounds, I’m unsuccessful at getting structures. When we’re trying to report these single-molecule magnets, structures are very, very critical because that field is very young. People don’t really understand what makes a good single-molecule magnet, so combining magnetic measurements with really good structural data is important,” Murillo explained.
Oscar S. Hernández-Daguer
Jesse Murillo (left) with Dr. Yu-Sheng Chen
Murillo’s stay coincided with visits by other students and professors who were also involved in summer research programs supported by ChemMatCARS but whose materials were quite different. “I was able to learn much about different approaches to collecting and analyzing data from single-crystal x-ray diffraction experiments. Additionally, I had many delightful conversations with them about their science, universities, and their various career experiences and future goals,” Murillo wrote in a summary of the visit.
Hernández-Daguer had broader goals for his visit, because he arrived at Sector 15 in the midst of a “career transition” in his graduate studies. In the course of his master’s work in solid state physics, he learned to do single-crystal x-ray diffraction…and fell in love. “My advisor, he was giving me a lot of books to understand that phenomenon [x-ray diffraction]. When I was reading about all of that, I was captivated. I was thinking just to continue working in solid state physics, but when I knew the x-ray physics world…now I want to work in that!” His imagination is brimming with ideas for x-ray microscopy, particularly to overcome challenges in recovering phase information from diffraction data. At ChemMatCARS he worked with a team directed by Mark Schlossman of the University of Illinois at Chicago; the team is developing a new measurement technique for high-energy x-ray scattering from aqueous solutions in reflection mode. The visit fulfills an option in his master’s program for practical training.
Both young researchers appreciated the unique opportunity for in-depth experience. Murillo now has a much better idea of how to make efficient use of beamtime while accommodating his delicate and short-lived samples. “This is kind of a unique situation we’re in, because we can do things that you typically won’t be able to do when you come as a user, like take the time to analyze data between runs or re-run crystals if we need to. All this experience is going to make my future trips much, much more efficient. I’ll know that it’s better to bring more than one person, and I’ll know how to prepare the samples best at my home institution. All of that is going to be key on my return trips as a user.”
Hernández-Daguer left feeling confident in his new vocation: “I feel so grateful to the researchers at ChemMatCARS, especially to Wei Bu, the beamline scientist who worked with me, for their disposition to teach me and to help me succeed in my project,” he wrote in his summary, adding, “This summer research internship in ChemMatCARS affirmed my wish to do my Ph.D. in the x-ray physics field and to want to continue working in a research environment like the one in APS.” Inspired by his summer mentors, he is considering a career as a beamline scientist.
Murillo went home with the best possible takeaway: publishable data. “Already, I am seeing some of the work from this visit making an impact. Some of the structures from data I collected are already included in prepared manuscript that will be submitted to a peer-reviewed journal,” Murillo wrote in his summary. But beyond the immediate reward of great data and a potential publication, he continued, “I have gained a broader perspective on what career paths are available to individuals in the science field. After my visit, I now see that careers at national laboratory facilities can be just as creatively rewarding experiences as those at academic research institutions.”
The annual Graduate Student Research Award at ChemMatCARS (GSRAC) program supports two graduate students to carry out their research and participate in other beamline activities at ChemMatCARS over an extended period of 4–6 weeks during the summer. This program allows students to pursue their PhD research and deepen their understanding of the sophisticated synchrotron x-ray techniques and capabilities at ChemMatCARS and the Advanced Photon Source. Preference is given to women and members of under-represented groups (URG), but all are encouraged to apply.