Q: What initially drew you to the APS? 

Ana: I first learned about the APS while I was working on my PhD in Brazil. At the time, I was interested in using techniques based on coherent X-rays, which were not yet available there. That led us to apply for beamtime at the APS, and in November 2016, I came to Argonne for the first time. It was also my first visit to the United States, which made the experience especially memorable. 

What attracted me to the APS was the ability to work with coherent X-ray beams. In practice, this means we can look inside individual nanocrystals and map how they are strained or distorted at the nanoscale. 

That capability was compelling because internal strain and defects can strongly influence how materials behave. Being able to visualize those features directly opened up new ways of studying structure-property relationships, which I wanted to pursue further. 

Q: Can you describe the research you’ve conducted at the APS?  

Ana: My research at the APS has focused on materials science, including studies of catalysts, battery materials, and minerals. Across these systems, the central question has been how internal defects and strain distributions inside nanomaterials relate to their properties and performance. 

A major part of this work has involved studying materials under operating conditions, such as catalysts during chemical reactions or battery materials during cycling. Rather than measuring average behavior across many particles, I’ve been interested in understanding how individual nanoparticles respond and why some behave differently from others. 

To do this, I’ve primarily used Bragg coherent diffraction imaging. This technique allows us to illuminate a single nanocrystal with a coherent X-ray beam, record its diffraction pattern, and reconstruct the particle in three dimensions. It provides access to internal strain and defect structures that are not visible in conventional laboratory X-ray measurements. 

Q: What role did the APS play in enabling or advancing your work?  

Ana: The APS has been essential to my research because coherent X-ray techniques depend critically on beam brightness, stability, and coherence. Even before the APS upgrade, it was a leading facility worldwide in these areas. 

Using APS beamlines, I was able to measure internal strain fields and defect distributions inside individual nanocrystals with high sensitivity. These measurements revealed how subtle structural variations influence how materials crack, react, or degrade over time—processes that are central to applications such as batteries and catalysis.  

Without the APS’s combination of coherence, brightness, and experimental stability, these measurements would not have been feasible. 

Q: Has anything unexpected come out of your work with the APS, either in your results or in the process itself? 

 Ana: One unexpected result came from experiments on individual calcite nanocrystals. Calcite is a common mineral, and based on prior knowledge, we expected its diffraction patterns to be relatively symmetric. Instead, we observed highly asymmetric diffraction patterns that initially seemed unusable. 

At first, we thought the data might not be useful. After further investigation, we found that the asymmetry revealed an unusual internal strain and defect distribution linked to the synthesis process used to produce the nanocrystals. 

What initially appeared to be “bad” data proved to be a valuable clue that led to a deeper understanding of the material’s internal structure. 

Q: What impact has your research at the APS had on your work so far? What are you excited about exploring next? 

 Ana: Working at the APS has shaped how I approach materials research. Coherent X-ray techniques have demonstrated the power of studying individual particles rather than relying solely on averaged measurements, and this perspective has influenced how I design experiments and frame scientific questions. 

Looking ahead, I’m especially excited about the possibilities enabled by the upgraded APS. Higher coherence and brightness will enable improved spatial and temporal resolution, allowing observation of smaller features and tracking faster changes within materials. 

As these capabilities continue to develop, we’ll be able to collect higher-quality data on more particles in less time. I see this as the beginning of a new phase for coherent X-ray methods.