Size-dependent properties of nanostructured metal particles

Ligand stabilized transition metal clusters exhibit size-dependent electron ic behaviour. From the current-voltage characteristics of a 17 nm Pd cluste r it can be followed that it behaves bulk-like at room temperature, but sho ws a Coulomb blockade at 4.2 K. Contrary to that, 1.4 nm Au clusters show a Coulomb blockade already at room temperature and a series of single electr on transitions at 90 K. Quantum size behaviour of a series of Pd clusters i s also demonstrated by specific heat and susceptibility measurements. Activ ation energies for electron transitions between three-dimensionally organiz ed 1.4 nm gold clusters, separated by spacer molecules of varying lengths, have been determined. Nanoporous alumina membranes serve as matrices to gen erate cluster wires which will be used to study electron transitions betwee n clusters in one dimension.