3-D crystal mapping gets a resolution boost

Compiled by Photonics Spectra staff

A newly developed technique for three-dimensional mapping of crystal structures provides resolution 100 times greater than that of existing nondestructive 3-D techniques, opening the door for more precise analysis of the structural parameters in nanomaterials.

Traditionally, it was only possible to see the crystal structure of materials by looking at a cut surface, which provided only two-dimensional information. In recent years, x-ray techniques have been developed to look inside a material and obtain 3-D maps of the structures. Until recently, these methods had resolution limitations of around 100 nm.

Now scientists at Risoe National Laboratory for Sustainable Energy at the Technical University of Denmark have developed a method that allows 3-D mapping of crystal structures inside a material down to nanometer resolution using a transmission electron microscope. Their research appeared in the April 1, 2011, issue of Science (doi: 10.1126/science.1202202).

Although samples must be thinner than a few hundred nanometers, this is not a problem for researchers investigating crystal structures inside nanomaterials because the average crystal size for these is typically less than 100 nm.

The ability to collect 3-D images of the crystal structure in these materials is an important step toward understanding the origins of their spectral properties. When able to directly observe changes taking place inside the material, scientists can repeat the method before and after heat treatments to see how heating alters the structure of nanomaterials.