Structure Control And Plasmonic Research Of Atomic-precise Gold Clusters

The research of nanomaterials has been in-depth,which plays an important role in the miniaturization of materials,and has also set off a wave of research in decades.However,at present,the physical properties of nanomaterials are mostly understood by the modification of classical theory,and the research of them is also limited to the rough size accuracy.At the same time,the research of clusters has been more than half a century.People have done extensive and profound research on this kind of novel materials which connect atoms and bulk analogues in theory and experiment.The properties of clusters are quite different from those of bulk analogues due to their electronic structures,which are significantly affected by the number of atoms and their symmetry.The effective understanding and utilization of these novel properties will greatly change human life.At present,with the development of computer technology,the theoretical calculation of clusters has been greatly strengthened.Also with the development of electron microscopy and the progress of cluster precise preparation technology,the experimental science of clusters has been developed synchronously.However,as the front of nanomaterials miniaturization,clusters still have a long way to go to people’s life.It is of great significance to replace nanofabrication with atomic fabrication,and to move towards the field of clusters that subvert the classical physical properties to novel quantum physics.Based on the aspects of the structure control of the atomic manufacturing clusters and the continuous research of the cluster properties changing with the number of atoms,we are committed to the exploration of the following aspects:（1）Participating in the debugging of time-of-flight mass selection cluster source,developing a number of cluster deposition devices,and realizing the preparation of a variety of atomic number precision clusters.（2）Based on the time-of-flight mass selection cluster source of magnetron sputtering of our research group,we adjust the structure of Au₉₂₃clusters with accurate atomic number.Through this study,we have preliminarily realized the transformation between the different structures of the cluster,that is,from the most stable ten facet to the metastable twenty facet under the normal preparation conditions.This study lays a foundation for the following precise control of cluster structure,which makes the cluster move from atomic precision to structural precision（3）We have quantitatively studied the plasmonic response of atomic-precise gold clusters from 70000 to 100 atoms by using the electron energy loss spectrum.In this study,we obtain three evolutionary regimes with two clear boundaries.They are the boundaries between bulk metal and molecular like clusters,classical and quantum properties,respectively.At the same time,we quantitatively observed the scaling rate of the excitation probability of the surface plasmon of the gold cluster versus the number of atoms in the experiment.This strict mathematical dependence shows the general rule of the cluster rich properties.