Comparing the fragmentation chemistry of gas-phase adducts of poly(dimethylsiloxane) oligomers with metal and organic ions

2009 ◽  
Vol 87 (2) ◽  
pp. 453-459 ◽  
Author(s):  
Justin Renaud ◽  
Abdulhrahman M. Alhazmi ◽  
Paul M. Mayer
Keyword(s):  
Gas Phase ◽  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Laboratory Frame ◽  
Fragment Ions ◽  
Gas Phase Ions ◽  
Fragmentation Chemistry ◽  
Secondary Ion ◽  
Cyclic Fragment ◽  
End Group

Gas-phase ions of poly(dimethylsiloxane) oligomers were formed by electrospray ionization either by protonating them in solution with formic acid or by generating adducts of the oligomers with the metal ions Li+, Na+, K+, and Ag+ as well as with the organic cations NH4+, CH3CH2NH3+, and protonated glycine, aspartic acid, and 1,2-diphenylethylamine. The collision-induced fragmentation of the oligomeric ions was strongly dependent on the nature of the charging species. Ag+ adducts dissociated in a manner previously observed in secondary ion mass spectrometry experiments generating a series of linear and cyclic fragment ions, while Li+ adducts fragmented to form two ions: an adduct of the metal ion with the oligomer end-group and one with the remaining oligomer. Na+ and K+ adducts simply dissociate to form the bare metal ion. The organic species, to varying extents, transfer the proton to the oligomer to form a protonated poly(siloxane) ion. These protonated oligomers then dissociate at very low laboratory-frame collision energy along the siloxane backbone by loss of a silanol. These backbone fragments can then lose a methyl group to form a second series of fragment ions. Suggestions for probable mechanistic pathways for these processes are presented.

Aspects of high-resolution imaging with a scanning ion microprobe

1986 ◽  
Vol 44 ◽  
pp. 750-751
Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
Y. L. Wang
Keyword(s):  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Chromatic Aberration ◽  
Ion Source ◽  
Ion Microprobe ◽  
Emission Pattern ◽  
Intrinsic Resolution ◽  
Resolution Imaging ◽  
20 Nm ◽  
Secondary Ion

We have shown the feasibility of 20 nm lateral resolution in both topographic and elemental imaging using probes of this size from a liquid metal ion source (LMIS) scanning ion microprobe (SIM). This performance, which approaches the intrinsic resolution limits of secondary ion mass spectrometry (SIMS), was attained by limiting the size of the beam defining aperture (5μm) to subtend a semiangle at the source of 0.16 mr. The ensuing probe current, in our chromatic-aberration limited optical system, was 1.6 pA with Ga+ or In+ sources. Although unique applications of such low current probes have been demonstrated,) the stringent alignment requirements which they imposed made their routine use impractical. For instance, the occasional tendency of the LMIS to shift its emission pattern caused severe misalignment problems.

Phosphorous and Boron Incorporation and its Effect on Optical Properties of Ge:H and Si0.01Ge0.99:HFilms Deposited by LF PECVD

2012 ◽  
Vol 1372 ◽  
Author(s):  
Nery Delgadillo ◽  
Andrey Kosarev ◽  
Afonso Torres ◽  
Lancelot Garcia ◽  
Brian Gonzales
Keyword(s):  
Gas Phase ◽  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Chemical Vapour ◽  
Low Frequency ◽  
Localized States ◽  
Optical Measurements ◽  
Band Tail ◽  
Frequency Plasma ◽  
Secondary Ion

ABSTRACTDeposition conditions that provided low absorption related to both band tail and deep localized states have been found for both materials Ge:H and Si1YGeY:H. Phosphorous incorporation on Si0.01Ge0.99:H films and boron incorporation on Ge:H films were deposited by low frequency plasma-enhanced chemical vapour deposition (LF PECVD). The phosphorous incorporation in solidphase was observed to preferential with the increase of the doping in the gas phase to 2.5 %, and 2.5% to 4% was observed preferential Si0.01Ge0.99 film, boron incorporation in solid phase increase linearly with the increase of the doping gas phase. The content of solid phase was characterized by Secondary ion mass spectrometry (SIMS) profiling. Hydrogen concentration in the films was determined from Fourier transform infrared spectroscopy (FTIR) and SIMS measurements. Optical measurements provided optical gap, localized states, and band tail. A significant reduction of both band tail and deep localized states were observed at boron incorporation in solid phase = 0.004% on Ge:H films and the same were observed at phosphorous incorporation in solid phase = 0.29% on Si0.01Ge0.99:H films.

Secondary ion imaging microanalysis

1989 ◽  
Vol 47 ◽  
pp. 8-9
Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
C Girod-Hallegot ◽  
P. Hallegot ◽  
Y. L. Wang
Keyword(s):  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Sample Surface ◽  
Biological Tissues ◽  
Ion Source ◽  
Ion Imaging ◽  
Research Areas ◽  
Interdisciplinary Problems ◽  
20 Nm ◽  
Secondary Ion

The goals of high spatial resolution and high elemental sensitivity in the imaging microanalysis of biological tissues and materials have, to a large extent, been attained by using the method of secondary ion mass spectrometry (SIMS) following bombardment of a sample surface by a focused beam of heavy ions. The instrument that we will discuss and which has achieved these goals is a scanning ion microprobe originally developed in collaboration with Hughes Research Laboratories (UC-HRL SIM). It utilizes a 40-60 keV Ga+ probe, extracted from a point-like liquid metal ion source, that can be focused to a spot as small as 20 nm in diameter. During the past five years, much effort has been devoted to a reappraisal of well known SIMS methodologies in regard to their applicability to a range of lateral resolution (20-1000 nm) previously unexplored. Furthermore, of particular concern has been the identification of research areas whose demands could most profitably be matched by the performance of this new class of microprobes. The results of this effort are contained in over 21 topical publications and 14 review articles covering both instrumental aspects of our development and applications to a variety of interdisciplinary problems.

Evaluation of Segregation in Polycrystalline 10 mol% Yttria Doped Zirconia (10YSZ)

2011 ◽  
Vol 1363 ◽  
Author(s):  
Muhammad Asri Idris ◽  
Janusz Nowotny ◽  
Sean S. Li
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Surface Segregation ◽  
Secondary Ion Mass Spectrometry ◽  
Oxygen Activity ◽  
Concentration Gradients ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

ABSTRACTThe present work reports surface segregation in polycrystalline yttria-stabilised zirconia (cubic) including 10 mol% Y2O3 (10YSZ). The 10YSZ specimen was annealed in the range 1073 K - 1673 K in the gas phase of controlled oxygen activity. The segregation-induced intensity profiles of 89Y, 40Ca, 28Si, 27Al, 133Cs, 197Au and 90Zr was measured using secondary ion mass spectrometry (SIMS). The data obtained show that (i) annealing of 10YSZ results in the formation of segregation-induced concentration gradients of 89Y, 40Ca, 28Si, 27Al and (ii) segregation-induced profiles depend on oxygen activity.

Cesium liquid metal ion source for secondary ion mass spectrometry

1994 ◽  
Vol 65 (7) ◽  
pp. 2276-2280 ◽  
Author(s):  
Kaoru Umemura ◽  
Hiroyasu Shichi ◽  
Setsuo Nomura
Keyword(s):  
Mass Spectrometry ◽  
Liquid Metal ◽  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Source ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Liquid Secondary Ion Mass Spectrometry and Collision-induced Dissociation Mass Spectrometry of Sulfonamide Derivatives of meso-Tetraphenylporphyrin

1999 ◽  
Vol 03 (03) ◽  
pp. 172-179 ◽  
Author(s):  
M. ROSÁRIO M. DOMINGUES ◽  
M. GRAÇA SANTANA-MARQUES ◽  
A. J. FERRRER-CORREIA ◽  
AUGUSTO C. TOMÉ ◽  
MARIA G. P. M. S. NEVES ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Secondary Ion Mass Spectrometry ◽  
Molecular Ions ◽  
Collision Induced Dissociation ◽  
Fragment Ions ◽  
Ion Mass Spectrometry ◽  
Derivatives Of ◽  
Secondary Ion

Liquid secondary ion mass spectrometry (LSIMS) and collision-induced dissociation (CID) were used for the characterization of sulfonamide derivatives of meso-tetraphenylporphyrin (TPP). The spectra obtained using LSIMS show abundant molecular ions and fragment ions from losses of the sulfonamide moieties. The main fragmentation observed in the LSI mass spectra and in the CID spectra of the protonated or cationized molecules involves the loss of one sulfonamide group. In addition, in the CID spectra of these compounds the fragment ions formed by the elimination of two, three and/or four sulfonamide groups are also observed. The CID spectra of the protonated or cationized molecules of these derivatives do not display the ions formed by the cleavage of the S - N bond which have been reported for other sulfonamide compounds. The LSI mass spectra and CID spectra of sulfonamide derivatives of meso-tetraphenylporphyrin provide an easy and reliable means of identification of the number and nature of sulfonamide groups in the porphyrinic ring.

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