5.5 Analogy Considerations

After all these investigations of the influence of certain parameters on meta-stable cluster states it might be helpful to build some vivid connections.

Looking through the previous MD results, a certain analogy can be drawn between the meta-stable cluster states and the excited states of atoms (see Fig. 5.26):

• The potential energies of the meta-stable (excited) states are larger than those of the stable (ground) state.

• After a certain period the clusters (atoms) transit from their meta-stable (excited) states into the stable (ground) state without external influence, the atoms by emitting photons, the clusters by increasing their temperature.

• The period (lifetime) of the meta-stable (excited) states is not constant, but probability distributed. More or less, all intervals are possible, but the values with maximum probability are most likely to appear.

• The transition from meta-stable (excited) to the stable (ground) state can be triggered by an appropriate stimulation, the electrons by photons of certain wave lengths, the clusters by a local perturbation of the surface.

Figure 5.26: The analogy between nano-clusters and atoms: The potential energy of both, the meta-stable cluster state and the excited state of atoms, is on a higher level than the according stable state and ground state, respectively. After a certain time (meta-stable period for clusters and lifetime for excited atoms, respectively) transitions into the lower energy states take place without external influence. The atoms emit photons, the clusters increase their temperature. (More details are given in the text.) Further, the transition of meta-stable...