Secondary ion mass spectrometry of metal halides. 1. Stability of alkali iodide clusters

Barlak, T. M.; Campana, Joseph E.; Colton, Richard J.; DeCorpo, J. J.; Wyatt, J. R.

doi:10.1021/j150625a026

Cited by 83 publications

(28 citation statements)

References 5 publications

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“…Table I1 lists the ion intensity ratios &/I5, &/Is, and Ilz/Ill for the alkali iodides as a function of the alkali metal. The two unimolecular dissociation channels are (1) Na+ ion emission (1) [Na(NaCl),]+ -(NaCl), + Na+ Table I11 contains the data relevant to the energy barrier calculations. This phenomenon is illustrated by the data in Figure 5 which show intense ions at n = 6,9, and 12 only in the CsI data.…”

Section: Resultsmentioning

confidence: 99%

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

Barlak¹,

Campana²,

Wyatt³

et al. 1983

J. Phys. Chem.

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Section: Resultsmentioning

confidence: 99%

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

Barlak¹,

Campana²,

Wyatt³

et al. 1983

J. Phys. Chem.

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“…Large clusters of these materials were first produced by bombardment of crystalline targets with Xe ϩ ions and detected by means of secondaryion mass spectrometry. [1][2][3] The mass spectra showed anomalies in the cluster intensities for certain values of n, which were tentatively interpreted as revealing the enhanced stability of ''cuboidlike'' structures. The results were explained in terms of a direct emission model, which assumes that cuboidlike cluster ions are directly sputtered from the crystal.…”

Section: Introductionmentioning

confidence: 90%

Ab initiocalculations of structures and stabilities of(NaI)nNa+
Aguado
¹
,
Ayuela
²
,
López
³

et al. 1998
Phys. Rev. B
40
10
59
0
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Ab initio calculations using the perturbed ion model, with correlation contributions included, are presented for nonstoichiometric (NaI) n Na ϩ and (CsI) n Cs ϩ (nр14) cluster ions. The ground state and several low-lying isomers are identified and described. Rocksalt ground states are common and appear at cluster sizes lower than in the corresponding neutral systems. The most salient features of the measured mobilities seem to be explained by arguments related to the changes of the compactness of the clusters as a function of size. The stability of the cluster ions against evaporation of a single alkali halide molecule shows variations that explain the enhanced stabilities found experimentally for cluster sizes nϭ4, 6, 9, and 13. Finally, the ionization energies and the orbital eigenvalue spectrum of two (NaI) 13 Na ϩ isomers are calculated and shown to be a fingerprint of the structure.

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“…The fall with increasing t is slower than for Si since the binding energy of Ge, at 3.81 eV, is significantly lower than that at 4.66 eV for Si. The correlation of the cluster structures and their stabilities in the emitted secondary ion intensity was seen, earlier, in the studies of alkali halides by Barlak et al [34,46]. There, stable, low-energy cubic-like h ϫ k ϫ l filled structures were observed where h, k, and l were all odd-numbered values.…”

Section: ‫ء‬mentioning

confidence: 54%

“…In this latter case, secondary ion molecular fragments (CsI) t I Ϫ were analyzed for 1 Յ t Յ 12. That the alkali halides, in general show power law spectra for 4 keV Ar ϩ and Xe ϩ primary ions was first shown by Barlak et al [34,35].…”

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confidence: 84%

Relationships between cluster secondary ion mass intensities generated by different cluster primary ions

Seah

Green

Gilmore

2010

J. Am. Soc. Mass Spectrom.

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Measurements are described to evaluate the constitution of secondary ion mass spectra for both monatomic and cluster primary ions. Previous work shows that spectra for different primary ions may be accurately described as the product of three material-dependent component spectra, two being raised to increasing powers as the cluster size increases. That work was for an organic material and, here, this is extended to (SiO 2 ) t OH Ϫ clusters from silicon oxide sputtered by 25 keV Bi n ϩ cluster primary ions for n ϭ 1, 3, and 5 and 1 Յ t Յ 15. These results are described to a standard deviation of 2.4% over 6 decades of intensity by the product of a constant with a spectrum, H SiOH ‫ء‬ , and a power law spectrum in t. This evaluation is extended, using published data for Si t ϩ sputtered from Si by 9 and 18 keV Au Ϫ and Au 3 Ϫ , with confirmation that the spectra are closely described by the product of a constant with a spectrum, H Si ‫ء‬ , and a simple spectrum that is an exponential dependence on t, both being raised to appropriate powers. This is confirmed with further published data for 6, 9, 12, and 18 keV Al Ϫ and Al 2 Ϫ primary cluster ions. In all cases, the major effect of intensity is then related to the deposited energy of the primary ion at the surface. The constitution of SIMS spectra, for monatomic and cluster primary ion sources, is shown, in all cases, to be consistent with the product of a constant with two component spectra raised to given powers. (J Am Soc Mass Spectrom 2010, 21, 370 -377) © 2010 American Society for Mass Spectrometry T he analysis of complex molecules in SIMS has been enhanced in recent years by the application of primary cluster ions of the type Au n Ϯ , Bi n ϩ , C 60 nϩ , etc. These provide significantly higher yields of the larger fragments that are important in the analysis of larger molecules. Over the years, there has not been a great focus on the relative intensities of the many secondary ions in the spectrum and their changes with the change in primary ion cluster size and energy. Analysts have usually focused on the enhancement of intensity of a particular characteristic ion obtained when using larger cluster primary ions. However, the fragment ions in the spectrum can be used to construct the structure of the molecules or the arrangement of atoms at a surface as well as provide important data as a function of depth in depth profiles [1][2][3][4][5][6][7][8]. Studies of the whole secondary ion spectrum and its evolution from one primary ion source to another are an important part of the infrastructure to the whole field of secondary ion mass spectrometry.Much historical data and data in spectral libraries [9 -11] are for inert gas primary ions. Over the years, the primary ion sources used have changed and changed again. Different spectrometer manufacturers fit different primary ion sources. It is important, therefore, if analysts are to make the best use of their instruments and of the published literature and data sources, that the relationships for the secondary ion ...

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Secondary ion mass spectrometry of metal halides. 1. Stability of alkali iodide clusters

Cited by 83 publications

References 5 publications

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

Ab initiocalculations of structures and stabilities of(NaI)nNa+
Aguado
¹
,
Ayuela
²
,
López
³

et al. 1998
Phys. Rev. B
40
10
59
0
View full text Add to dashboard Cite

Relationships between cluster secondary ion mass intensities generated by different cluster primary ions

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Secondary ion mass spectrometry of metal halides. 1. Stability of alkali iodide clusters

Cited by 83 publications

References 5 publications

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

Secondary ion mass spectrometry of metal halides. 3. Ionic radii effects in alkali halide clusters

Ab initiocalculations of structures and stabilities of(NaI)nNa+Aguado1, Ayuela2, López3 et al. 1998Phys. Rev. B4010590View full textAdd to dashboardCite

Relationships between cluster secondary ion mass intensities generated by different cluster primary ions

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About

Ab initiocalculations of structures and stabilities of(NaI)nNa+
Aguado
¹
,
Ayuela
²
,
López
³

et al. 1998
Phys. Rev. B
40
10
59
0
View full text Add to dashboard Cite