scholarly journals Multiphoton Ionization Mass Spectrometric (MPIMS) Study of Phenol: Mechanism of Ionic Fragment Formation

1983 ◽  
Vol 3 (1-6) ◽  
pp. 29-47 ◽  
Author(s):  
R. S. Pandolfi ◽  
D. A. Gobeli ◽  
Jonathan Lurie ◽  
M. A. El-Sayed
Keyword(s):  
Laser Pulse ◽  
Energy Levels ◽  
Multiphoton Ionization ◽  
Pulsed Laser ◽  
Ionic Species ◽  
Low Energy ◽  
Ionization Mass ◽  
Fragmentation Pattern ◽  
Dissociation Channel ◽  
532 Nm

Time of flight (TOF) mass spectrometry is used in conjunction with a variable repelling voltage technique to elucidate the mechanism by which phenol ionizes and dissociates under 266 nm pulsed laser irradiation in combination with a 532 nm or 355 nm pulsed laser. The results suggest that, like benzene, the molecular ion is the predominant precursor of all ionic species generated in the process. Predominance of C5Hx+ species at relatively low powers confirms the presence of a low energy dissociation channel involving the elimination of CO. The use of a second laser at 532 nm is found to selectively destroy the C5Hx+ (as compared to the parent ion) species. The parent ion is found to be protected from the radiation of the second laser pulse at 532 nm but not at 355 nm if the second laser pulse is delayed by 50 ns. This is explained in terms of relaxation within the parent ion energy levels, the location of a low energy dissociation channel and the wavelengths of the lasers used. The main aspects of the fragmentation pattern are discussed in terms of the statistical theory of Rebentrost and Ben-Shaul.

Multiphoton ionization mass spectra of n-C 3 H 7 I and i-C 3 H 7 I at 532 nm

1998 ◽  
Vol 7 (4) ◽  
pp. 271-276 ◽  
Author(s):  
Zhang Lian-di ◽  
Wei Jie ◽  
Jiang Yun-yun ◽  
Fang Li ◽  
Zhang Shu-dong ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Multiphoton Ionization ◽  
Ionization Mass ◽  
532 Nm

Thin-Film Deposition Via Pulsed Laser Ablation

1996 ◽  
Vol 441 ◽  
Author(s):  
V. G. Panayotov ◽  
M. C. Kelly ◽  
G. G. Gomlak ◽  
T. L. T. Birdwhistell ◽  
B. D. Koplitz
Keyword(s):  
Thin Film ◽  
Laser Ablation ◽  
Experimental Approach ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Ionic Species ◽  
Film Deposition ◽  
Original Sample ◽  
532 Nm

AbstractWe report on a novel experimental approach for thin-film deposition via pulsed laser ablation. A combination of design features including the incorporation of original sample manipulation methods as well as enhanced analytical capabilities allow for experimental control and flexibility for thin-film deposition studies of a variety of materials. Here, the application is illustrated with a study of 532 nm pulsed laser ablation and subsequent deposition of CdTe.Conditions have been found that produce a mildly energetic ablation plume, and the average kinetic energies for the neutral and ionic ablation species in the plume have been determined to be approximately 2 and 11 eV, respectively. It has been shown that in the presence of an electric field the ionic species can be diverted away from the detector (and subsequently from the eventual deposit). Thin film deposits clearly reveal an increase in the number of sub-micron particles when direct ablation ions contribute to the deposition. The possibility for extraction of ablation ions and preparation of ablation plumes of neutrals only has been clearly demonstrated.

scholarly journals Effects of Accumulated Energy on Nanoparticle Formation in Pulsed-Laser Dewetting of AgCu Thin Films

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
H. K. Lin ◽  
C. W. Huang ◽  
Y. H. Lin ◽  
W. S. Chuang ◽  
J. C. Huang
Keyword(s):  
Pulsed Laser ◽  
Blue Shift ◽  
High Energy ◽  
Low Energy ◽  
Nanoparticle Formation ◽  
Energy Accumulation ◽  
Glass Substrates ◽  
Peak Absorption ◽  
Two Peaks ◽  
Sputtering System

AbstractAg50Cu50 films were deposited on glass substrates by a sputtering system. Effects of accumulated energy on nanoparticle formation in pulse-laser dewetting of AgCu films were investigated. The results showed that the properties of the dewetted films were found to be dependent on the magnitude of the energy accumulated in the film. For a low energy accumulation, the two distinct nanoparticles had rice-shaped/Ag60Cu40 and hemispherical/Ag80Cu20. Moreover, the absorption spectra contained two peaks at 700 nm and 500 nm, respectively. By contrast, for a high energy accumulation, the nanoparticles had a consistent composition of Ag60Cu40, a mean diameter of 100 nm and a peak absorption wavelength of 550 nm. Overall, the results suggest that a higher Ag content of the induced nanoparticles causes a blue shift of the absorption spectrum, while a smaller particle size induces a red shift.

Effect of pulsed laser target cleaning on ionisation and acceleration of ions in a plasma produced by a femtosecond laser pulse

2005 ◽  
Vol 35 (10) ◽  
pp. 953-958 ◽  
Author(s):  
Roman V Volkov ◽  
A A Vorobiev ◽  
Vyacheslav M Gordienko ◽  
M S Dzhidzhoev ◽  
I M Lachko ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulsed Laser ◽  
Laser Target

Low-energy femtosecond pulsed laser deposition of cerium (IV) oxide thin films on silicon substrates

2021 ◽  
pp. 126323
Author(s):  
Joseph A. De Mesa ◽  
Angelo P. Rillera ◽  
Melvin John F. Empizo ◽  
Nobuhiko Sarukura ◽  
Roland V. Sarmago ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Low Energy ◽  
Laser Deposition ◽  
Silicon Substrates ◽  
Oxide Thin Films ◽  
Femtosecond Pulsed Laser

Low-energy levels and gamma transitions inCo58

1975 ◽  
Vol 11 (3) ◽  
pp. 1042-1047 ◽  
Author(s):  
B. J. Brunner ◽  
R. G. Arns ◽  
S. E. Caldwell ◽  
C. M. Rozsa ◽  
J. W. Smith ◽  
...  
Keyword(s):  
Energy Levels ◽  
Low Energy ◽  
Gamma Transitions

Search for Melanoma Markers in Plasma and Serum Samples

2005 ◽  
Vol 11 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Roberta Seraglia ◽  
Susanna Vogliardi ◽  
Graziella Allegri ◽  
Stefano Comai ◽  
Mario Lise ◽  
...  
Keyword(s):  
High Frequency ◽  
Healthy Subjects ◽  
Ionic Species ◽  
Low Molecular Weight ◽  
Ionization Mass ◽  
Plasma Samples ◽  
Serum Samples ◽  
Blood Samples ◽  
Melanoma Patients ◽  
Diagnostic Ions

Fourteen blood samples from patients with melanomas and 11 blood samples from healthy subjects were analyzed by matrix-assisted laser desorption/ionization mass spectrometry. The study focussed on species of low molecular weight, in the 800–5000 Da range, present in plasma and sera. While for healthy subjects plasma samples lead to the production of a higher number of ionic species, for melanoma patients a high number of diagnostic ions, present with high frequency and with quite high relative abundance, are present, in particular, in serum samples and, to a lesser extent, also in plasma. Since plasma samples are obtained more easily in comparison to sera, it is possible to suggest that plasma can also be used for these studies.

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