scholarly journals Ion-Size Effects in the Growth Sequences of Metal-Ion-Doped Noble Gas Clusters

1997 ◽  
Vol 17 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Christian Lüder ◽  
Dimitris Prekas ◽  
Michalis Velegrakis
Keyword(s):  
Metal Ion ◽  
Mass Spectra ◽  
Noble Gas ◽  
Magic Number ◽  
Sphere Packing ◽  
Cluster Ions ◽  
Magic Numbers ◽  
Gas Clusters ◽  
The Stability ◽  
Ion Size

We have studied the stability and the structure of doped noble gas cluster ions of the type M+Xn, (M=In, Al, Na, X=Ar, Kr, Xe) by systematically changing the composition M/X and observing changes in the magic number patterns appearing in the mass spectra. When the metal ion radius is comparable to the radius of the noble gas atom, the mass spectra show the familar icosahedral magic numbers n+ 1=13,19,23,26,29,32, 46, 55,... In constrast, for metal ions with radii significantly smaller than the noble gas atoms, we observe a new series of magic numbers n + 9, 11, 17, 21,24, 26,... This series converts into the icosahedral one for larger clusters. Using a simple hard sphere packing model, we show that this new series of magic numbers is consistent with a cluster growth sequence which is based on a capped square antiprism (CSA) geometrical structure of the clusters.

The Stability of Rare Gas Clusters by Ionization

1985 ◽  
Vol 40 (5) ◽  
pp. 516-519 ◽  
Author(s):  
E. E. Polymeropoulos ◽  
S. Löffler ◽  
J. Brickmann
Keyword(s):  
Computer Simulations ◽  
Cluster Size ◽  
Mass Spectra ◽  
Rare Gas ◽  
Magic Numbers ◽  
Dissociation Dynamics ◽  
Charged Clusters ◽  
Singly Charged ◽  
Gas Clusters ◽  
The Stability

Computer simulations of the dissociation dynamics of argon and xenon neutral and singly charged clusters with 5 - 20 atoms were performed. It is shown that the stability of clusters with ‘magic numbers’ of atoms (n = 19 for argon, and n = 13,19 for xenon) as found in TOF mass spectra, is more enhanced by ionization than that of their neighbours, indicating the importance of the ionization for the cluster size distribution found in experiments.

First and Second Ionization Potentials, Reactions, and Surface Collisions of C60 and Related Clusters

1990 ◽  
Vol 206 ◽  
Author(s):  
Stephen W. McElvany ◽  
Mark M. Ross ◽  
John H. Callahan
Keyword(s):  
Mass Spectra ◽  
Magic Number ◽  
Chemical Properties ◽  
Cluster Ions ◽  
Magic Numbers ◽  
The Past ◽  
Spectroscopic Identification ◽  
Physical And Chemical ◽  
Experimental And Theoretical Studies ◽  
And Chemical Properties

The physical and chemical properties of large carbon clusters, Cn(n>40), have been studied extensively over the past six years. The spherical nature of these clusters has been debated and inferred from both experimental and theoretical studies until the recent isolation and subsequent spectroscopic identification of bulk C60 and C70. Although the n=60 and 70 cluster ions are anomalously abundant (“magic numbers”) in the mass spectra and are proposed to be highly symmetric species, the other “magic number” clusters have yet to be isolated.

A thermodynamic approach to mechanical stability of nanosized particles

Open Physics ◽  
2003 ◽  
Vol 1 (2) ◽  
Author(s):  
Vladimir Samsonov ◽  
Nikolay Sdobnyakov
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Stability Condition ◽  
Mechanical Stability ◽  
Noble Gas ◽  
Stability Limit ◽  
Gas Clusters ◽  
The Stability ◽  
The Second Variation ◽  
Nonpolar Organic

AbstractThermodynamic stability conditions for nanoparticles (resulting from non-negativity of the second variation of the free energy) have been analyzed for two cases: (i) a nonvolatile nanosized particle with the size-dependent surface tension; (ii) the limiting case of larger objects when the surface tension takes its macroscopic value. It has been shown that the mechanical stability of a nanoparticle, i.e. its stability relative to the volume fluctuations, is defined by an interplay between the excess (“surface”) free energy and the volumetric elastic energy. According to the results obtained, noble gas clusters and metal nanoparticles satisfy the mechanical stability condition. At the same time, water nanodrops, as well as nanoparticles presented by nonpolar organic molecules, correspond to the stability limit. Among the investigated systems, the stability condition is not carried out for n-Pentane clusters.

A NEW APPROACH OF THE SIMS METHOD FOR METAL CLUSTERS

1996 ◽  
Vol 03 (01) ◽  
pp. 551-555
Author(s):  
I. KATAKUSE ◽  
T. ICHIHARA ◽  
H. ITO ◽  
T. SAKURAI ◽  
T. MATSUO
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Metal Clusters ◽  
Secondary Ion Mass Spectrometry ◽  
Shell Structures ◽  
Cluster Ions ◽  
Magic Numbers ◽  
Size Distributions ◽  
New Approach ◽  
Secondary Ion

The size distributions of ( CsI )n Cs +, [Formula: see text], and [Formula: see text] (M: alkali metal, j=1, 2, 3, 4, 5) clusters were obtained using secondary-ion mass spectrometry. The sizes of stable neutral clusters ( CsI )n and ( Hg )n clusters were determined from the mass spectra of cluster ions ( CsI )n Cs + and ( Hg )nM+. The magic numbers of [Formula: see text] clusters were identical to those of van der Waals type clusters. It is believed that the shell closing cluster [Formula: see text] is at the center of complex clusters [Formula: see text]. The [Formula: see text] clusters were believed to have electronic shell structures from the magic numbers.

Noble Gas Clusters Doped with a Metal Ion I:  Ab Initio Studies of Na+Arn

2004 ◽  
Vol 108 (4) ◽  
pp. 683-690 ◽  
Author(s):  
Takeshi Nagata ◽  
Mutsumi Aoyagi ◽  
Suehiro Iwata
Keyword(s):  
Ab Initio ◽  
Metal Ion ◽  
Noble Gas ◽  
Gas Clusters

Unimolecular decay of metastable Ar cluster ions. Evolution of magic numbers in Ar cluster mass spectra

1986 ◽  
Vol 74 (2-3) ◽  
pp. 281-301 ◽  
Author(s):  
T.D. Märk ◽  
P. Scheier ◽  
K. Leiter ◽  
W. Ritter ◽  
K. Stephan ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Cluster Ions ◽  
Magic Numbers ◽  
Cluster Mass

scholarly journals Appearance / Disappearance of Magic Number in Light Nuclei

2021 ◽  
Vol 9 (1) ◽  
pp. 109-115
Author(s):  
C. Karthika ◽  
C. Kokila ◽  
M. Balasubramaniam
Keyword(s):  
Ion Beam ◽  
Magic Number ◽  
Energy Difference ◽  
Light Nuclei ◽  
Magic Numbers ◽  
Shell Closure ◽  
Characteristic Features ◽  
The Stability ◽  
Nucleon Separation Energy ◽  
Stability Line

The shell structure of a nucleus is important to study their observed characteristic features. The classic magic numbers are successful in explaining the nuclear properties for nuclei lying near the stability line. The advent of radioactive ion beam facilities has permitted to examine nuclei in their extreme proton to neutron ratio. The light exotic nuclei were found to exhibit unique shell closure behaviour which is different from the medium mass nuclei near the stability line. The two nucleon separation energy difference systematics was used as a probe to study the magic character of light nuclei. New proton and neutron magic numbers were predicted among the available even Z isotopes and even N isotones. For certain systems, the classic magic numbers were found to be non-magic, while for some systems the magic property is retained even at the drip lines. The shell closure behaviour predicted is found to depend on the version of the mass table.

Structure of the complexes of ethylenediphosphinetetraacetic acid in solution

1985 ◽  
Vol 50 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Jana Podlahová ◽  
Josef Šilha ◽  
Jaroslav Podlaha
Keyword(s):  
Metal Ion ◽  
Carboxyl Groups ◽  
Complex Solution ◽  
Square Planar ◽  
Weak Complexes ◽  
Carboxylic Groups ◽  
Uv Visible ◽  
The Stability ◽  
Tetrahedral Complexes ◽  
Free Carboxyl

Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

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