Surface Science 156 (1985) 580 583 North-Holland, Amsterdam THE
STABILITY
S. M U K H E R J E E
OF CHARGED
and K.H.
METALLIC
CLUSTERS
BENNEMANN
lnstitut fur Theoretische Phvsik, Freie Unit,ersiti~t Berlin, A rnimalle 14. D-1000 Berlin 33, Germativ Received 19 July 1984
A simple theory is presented for explaining recent experimental results on the stability of charged metallic clusters. Calculations show that the stability of charged metallic clusters depends on the shape and electronic screening of the Coulomb interaction.
CHEMISTRY IN A CLUSTER BEAM T.P. MARTIN Max - Planck - lnstitut fur FestkOrperforschung, D- 7000 Stuttgart 80, Fed. Rep. of German), Received 9 July 1984
C o m p o u n d clusters have been produced by combining two elements in the vapour phase. The composition of the clusters was determined in a mass spectrometer. By controlling the vapour pressures of the two elements, it is possible to test rapidly the stability of compounds of all conceivable compositions. For example, Cs vapour has been allowed to react with 02, C12, Ss, H 2 0 , and 1'4- Analysis of the resulting cluster mass spectra allows us to deduce rules for the stability of metal-rich clusters and to identify new building blocks for the synthesis of solids.
590 NICKEL
Surface Science 156 (1985) 590-596 North-Holland. A m s t e r d a m 3d ELECTRON
DISTRIBUTION
OF SMALL
E M B E D D E D IN SiO A N D OF BULK N I C K E L - S i O D. FARGUES,
F. VERGAND
PARTICLES INTERFACE
and C. BONNELLE
Laboratoire de Chimie Physique de l'Unil~ersitb Pierre et Marie Curie. UA 170, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 0_5, France
Received 10 July 1984 The electron distribution of the 3d filled and empty states of nickel in small particles embedded in SiO is reported. It is compared to those of bulk metal and nickel atoms present at the bulk N i - S i O interface. The localisation of the 3d states increases with decreasing size in the range 200 to less than 100 atoms. A degeneracy removal of the 3d states giving rise to fine structures both in emission and photoabsorption spectra is evidenced in the smallest particles. An interatomic transition involving a charge transfer is seen at the bulk nickel SiO interface but not in the small particles.