QUENCHING OF THE SIZE EFFECTS IN FREE AND MATRIX-EMBEDDED SILVER CLUSTERS

The surface plasmon energy of silver clusters is investigated in the f ramework of the time-dependent local density approximation. The result s are in good agreement with experimental data on free Ag-N(+) cluster s and on Ag-N clusters embedded in solid argon and alumina. The size e ffects are weak and very sensitive to tile matrix, the porosity at the interface, and the cluster charge. It is shown that the core-electron contribution to the metal dielectric function is mainly responsible f or the quenching of the size effects in the optical response.