Regular nanocluster networks on Pb/Si(111)-Pb3√x3√ at low temperatures

We have observed the formation of highly regular networks of Pb clusters, which extend up to 100 nm in linear size, during the growth of Pb on the Si(111)-Pbα3√x3√ phase at low temperatures 115 K<T<250 K. The cluster networks are a metastable phase before the first preferred height of two-step Pb islands form as a result of quantum size effects. The cluster networks provide an easy kinetic pathway for the buildup of the two-step islands. The driving force for the formation of the cluster networks is most likely the long range elastic interaction between the Pb atoms mediated through the strained substrate