The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles
Journal of Materials Chemistry :: Sep 6, 2011
ITHACA, NY (Journal of Materials Chemistry) -- The recent work by Richard Robinson and Richard Hennig collaborating in the CCMR Growth Dynamics IRG is featured on the cover of the Journal of Materials Chemistry. In the paper they study the chemical transformation in nanoparticles using complementary characterization and analysis methods (EXAFS, HRTEM, XRD, and DFT) to uncover a two-step transition during the formation of hollow nanoparticles, known as the "Kirkendall effect." The hollowing is due to asymmetric diffusivities of cations and anions, and was previously not known to proceed in two separate stages. They found a metastable state that occurs just before this hollowing begins. This interesting metastable material has an amorphous shell and a crystalline core that will be useful for tailoring the properties of nanoparticles for energy applications.
Full publication: http://pubs.rsc.org/en/content/articlepdf/2011/jm/c1jm10337g