Vasyutin E. Charging and size effects in the metal cluster structures

The influence of the charging and size effects on the energy and transport characteristics of the nanostructures is investigated. It is calculated the ionization potential of a cluster and the electron affinity as a function of cluster's shape. The shape of cluster varies from strongly flattened to elongated. Thus we have a monatomic slab at the beginning and monatomic chain at the end. It is demonstrated that the temperature gradient of the chemical potential of the low-dimensional systems can be both positive and negative, and at some temperatures it can change sign. A model of the Coulomb instability of charged metal clusters is developed with take into account the quantization of the electronic spectrum. The critical sizes of the positively and negatively charged clusters of Au, Ag, Al, Na, K and Pb are calculated. It is estimated the electrostriction phenomenon of the metal clusters embedded into the dielectric. Cluster's anomalous electrostriction (cluster's compression) is possible as a result of the charging. The effects of single-electron tunnel charging and Coulomb blockade in a cluster structure are studied with allowance for the quantization of the electronic levels in an island electrode. Restrictions associated with the Coulomb instability of a cluster are introduced into the theory in a simple way. We demonstrate that the current gap exhibits non-monotonic size dependences which are related to the quantization of the electron spectrum and the Coulomb blockade.