With dimensions measuring billionths of a meter, nanoparticles are way too small to see with the naked eye. Yet it is becoming possible for today’s scientists not only to see them, but also to look inside at how the atoms are arranged in three dimensions using a technique called nanocrystallography. Trouble is, the powerful machines that make this possible, such as x-ray synchrotrons, are only available at a handful of facilities around the world. The U.S. Department of Energy’s Brookhaven National Laboratory is one of them — home to the National Synchrotron Light Source (NSLS) and future NSLS-II, where scientists are using very bright, intense x-ray beams to explore the small-scale structure of new materials for energy applications, medicine, and more.
But a Brookhaven/Columbia Engineering School team of scientists, in collaboration with researchers at DOE’s Argonne National Laboratory (ANL) and Northwestern University, has also been working to develop nanocrystallography techniques that can be used in more ordinary science settings. They have shown how a powerful method called atomic pair distribution function (PDF) analysis — which normally requires synchrotron x-rays or neutrons to discern the atomic arrangements in nanoparticles — can be carried out using a transmission electron microscope (TEM) — an instrument found in many chemistry and materials science laboratories.