| Autor: |
Jensen KM; Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA., Juhas P; Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA., Tofanelli MA; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA., Heinecke CL; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA., Vaughan G; European Synchrotron Radiation Facility, 38043 Grenoble, France., Ackerson CJ; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA., Billinge SJ; Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA.; Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA. |
| Abstrakt: |
Ultra-small, magic-sized metal nanoclusters represent an important new class of materials with properties between molecules and particles. However, their small size challenges the conventional methods for structure characterization. Here we present the structure of ultra-stable Au144(SR)60 magic-sized nanoclusters obtained from atomic pair distribution function analysis of X-ray powder diffraction data. The study reveals structural polymorphism in these archetypal nanoclusters. In addition to confirming the theoretically predicted icosahedral-cored cluster, we also find samples with a truncated decahedral core structure, with some samples exhibiting a coexistence of both cluster structures. Although the clusters are monodisperse in size, structural diversity is apparent. The discovery of polymorphism may open up a new dimension in nanoscale engineering. |
