Size-dependent properties of nanostructured metal particles

Ligand stabilized transition metal clusters exhibit size-dependent electronic behaviour. From the current-voltage characteristics of a 17 nm Pd cluster it can be followed that it behaves bulk-like at room temperature, but shows 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 electron transitions at 90 K. Quantum size behaviour of a series of Pd clusters is also demonstrated by specific heat and susceptibility measurements. Activation energies for electron transitions between three-dimensionally organized 1.4 nm gold clusters, separated by spacer molecules of varying lengths, have been determined. Nanoporous alumina membranes serve as matrices to generate cluster wires which will be used to study electron transitions between clusters in one dimension.