Untitled

The European Physical Journal D

et al. 2001

Self Cite

Abstract. The decay pathway competition between monomer and dimer evaporation of photoexcited cluster ions Au + n , n = 2-27, has been investigated by photodissociation of size-selected gold clusters stored in a Penning trap. For n > 6 the two decay pathways are distinguished by their experimental signature in time-resolved measurements of the dissociation. For the smaller clusters, simple fragment spectra were used. As in the case of the other copper-group elements, even-numbered gold cluster ions decay exclusively by monomer evaporation, irrespective of their size. For small odd-size gold clusters, dimer evaporation is a competitive alternative, and the smaller the odd-sized clusters, the more likely they decay by dimer evaporation. In this respect, Au + 9 shows an anomalous behavior, as it is less likely to evaporate dimers than its two odd-numbered neighbors, Au

Section: Resultssupporting

confidence: 59%

Decay pathways of small gold clusters

Vogel

Hansen

The European Physical Journal D

et al. 2001

Self Cite

“…Other features belong to electronic shell closing of the valence electrons, e.g. n e =18 for Au 17 -and n e =34 for Au 33 -, that are well known from other gold-cluster studies [11,12,13,14,15]. These structures in the abundance spectrum indicate that gold clusters are very hot after laser ablation and cool by evaporation of neutral monomers, thus increasing the relative intensity of the smaller clusters and of clusters with a closed electronic shell, i.e.…”

Section: Resultsmentioning

confidence: 77%

Cluster calibration in mass spectrometry: laser desorption/ionization studies of atomic clusters and an application in precision mass spectrometry

Blaum

Analytical and Bioanalytical Chemistry

Huber

et al. 2003

Self Cite

For accurate mass measurements and identification of atomic and molecular species precise mass calibration is mandatory. Recent studies with laser desorption/ionization and time-of-flight analysis of cluster ion production by use of fullerene and gold targets demonstrate the generation of atomic clusters for calibration purposes. Atomic ion results from the Penning trap mass spectrometer ISOLTRAP, in which a carbon cluster ion source has recently been installed, are presented as an application in the field of precision mass spectrometry.

“…Furthermore, we plan to further study the properties of dianionic noble metal clusters by collisional activation as already applied to singly [19,20] and multiply charged cations [21,22], and by timeresolved laser measurements, which may lead to a study of a delayed response in analogy to the observation of delayed photodissociation [23][24][25]. First steps to this end have already been taken in the case of dianionic titanium clusters [10].…”

Section: Discussionmentioning

confidence: 99%

Observation of multiply charged silver-cluster anions

The European Physical Journal D

Schweikhard

Vogel

2001

Self Cite

Singly charged silver-cluster anions are produced in a laser vaporization source and transferred into a Penning trap. After size selection the clusters are subjected to an electron bath in the trap, which results in the attachment of further electrons. The relative abundance of dianions or trianions as a function of the clusters' size is analyzed by time-of-flight mass spectrometry. Silver-cluster dianions are observed for sizes n ≥ 24 and trianions for n > 100. In addition, a detailed study of the cluster sizes 24 ≤ n ≤ 60 shows a pronounced resistance to electron attachment for singly charged anions Ag − n with a closed electronic shell, in particular Ag − 29 , Ag − 33 , and Ag − 39 . Both the threshold size for the observation of dianionic silver clusters and the shell effects in the production yield correlate favorably with previous theoretical investigations of the respective electron affinities. PACS. 36.40.Wa Charged clusters -36.40.Qv Stability and fragmentation of clusters -36.40.Cg Electronic and magnetic properties of clusters