Spring 2013 - Nanoparticles
Emergent Atomic and Magnetic Structures, Division of Materials Sciences and Engineering
Electron microscopy is the primary analytical tool when working with materials at the nanometer to sub-angstrom length scales. Nanometer-sized specimens are normally prepared by placing a drop of nanoparticles suspension on a suitable electron microscopy (EM) grid and allowing it to dry to accommodate the high vacuum environment inside the TEM, required for electron imaging. At these conditions, solvent evaporation can induce unwanted aggregation of suspended nanoparticles. Analysis of such a system becomes challenging due to the presence of a large number of randomly oriented, overlapping features of interest.
We are working on optimization of the novel on-the-EM-substrate synthesis of magnetic iron oxides as a tool for direct evaluation of the individual templated magnetic nanocrystal formation and growth, free of artifacts associated with the conventional sample preparation and characterization. Controlled synthesis directly on the surface of the EM transparent surface allows for a strategic small-scale growth of the templated nanoparticles. This leads to a significant reduction of the overall number of the nanoparticles and their solvent-induced interactions and overlapping, enabling high-resolution specimen imaging. We will carry out electron microscopy analysis of specimens to identify suitable data collection regimes.
Program mentor: Tanya Prozorov, associate scientist, Ames Laboratory