UCLA physicists map the three dimensional atomic structure of an alloy for the first time: Researchers measured the coordinates of more than 23,000 atoms in a technologically important material

In the world of the very tiny, perfection is rare: virtually all materials have defects on the atomic level. These imperfections -- missing atoms, atoms of one type swapped for another, and misaligned atoms -- can uniquely determine a material's properties and function. Now, UCLA physicists and collaborators have mapped the coordinates of more than 23,000 individual atoms in a tiny iron-platinum nanoparticle to reveal the material's defects.
The results demonstrate that the positions of tens of thousands of atoms can be precisely identified and then fed into quantum mechanics calculations to correlate imperfections and defects with material properties at the single-atom level. This research will be published Feb 2. in the journal Nature.

Jianwei (John) Miao, a UCLA professor of physics and astronomy and a member of UCLA's California NanoSystems Institute, led the international team in mapping the atomic-level details of the bimetallic nanoparticle, more than a trillion of which could fit within a grain of sand.

"No one has seen this kind of three-dimensional structural complexity with such detail before," said Miao, who is also a deputy director of the Science and Technology Center on Real-Time Functional Imaging. This new National Science Foundation-funded consortium consists of scientists at UCLA and five other colleges and universities who are using high-resolution imaging to address questions in the physical sciences, life sciences and engineering.