3D imaging of crystal defects

A clever combination of existing techniques has produced three-dimensional atomic images of individual platinum nanoparticles, disclosing the atomic structure of crystal defects within them. See Letter p.74 A 3D view of crystalline nanoparticles This paper reports a new combination of established techniques capable of realizing three-dimensional (3D) images and movies of a nanoparticle at the atomic scale. By identifying 3D Bragg peaks — peaks on the curve plotting energy loss of the X-ray radiation during its travel through the target — in an electron tomographic reconstruction combined with 3D Fourier filtering, the authors observe nearly all the atoms in a polycrystalline platinum nanoparticle. The resulting images reveal features that are hidden in conventional two-dimensional projections, including the core structure of edge and screw dislocations and details of twin boundary structure in the core of the nanoparticle. Possible applications for the technique include materials sciences, nanoscience, solid-state physics and chemistry.