Angle resolved photoelectron spectroscopy of simple metal clusters
Final Report Abstract
We have studied the photon energy dependence of the photoelectron angular distributions of a range of cluster sizes and materials. A number of interesting findings have been made: 1. Already very small clusters like Na3- exhibit angular distributions which one would expect on the basis of a simple jellium model. 2. For oblate clusters the angular distributions allow to distinguish not only between different angular momentum states, but also between states with the same angular momentum, but different magnetic quantum numbers. This allows to identify the hybridization between different states, which in these clusters is determined by a rather strict selection rule determined by the symmetry of the deviation from a spherical shape. 3. Clusters of different simple metals exhibit close to identical energy dependencies of the angular distributions, if the final state wavelengths are scaled to the cluster radius, that is presented on a dimensionless scale. This underlines that the angular distributions follow a universal law, which is probably rather independent of multi-electron-dynamics effects. 4. Even complex systems like spherical transition metal doped silicon clusters exhibit angular distributions with quite some similarity to the universal ones observed for simple metal clusters. Deviations are probably due to the fact that the electronic states in these clusters have rather strongly mixed angular momentum characters. Angle-resolved photoelectron spectroscopy therefore proved to be an extremely powerful tool for the study of the electronic structure as well as dynamic effects in the photoemission of metal and semiconductor clusters.
Publications
- Hybridization of angular-momentum eigenstates in nonspherical sodium clusters. Phys. Rev. A 88, 043202 (2013)
C. Bartels, C. Hock, R. Kuhnen, M. Walter, and B. v. Issendorff
(See online at https://doi.org/10.1103/PhysRevA.88.043202) - Photoelectron Imaging Spectroscopy of the Small Sodium Cluster Anions Na3-, Na5-, and Na7-. J. Phys. Chem. A 118, 8270-8276 (2014)
C. Bartels, C. Hock, R. Kuhnen, and B. v. Issendorff
(See online at https://doi.org/10.1021/jp5010902)
