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Author Shazali, I.; Van 't dack, L.; Gijbels, R.
Title Determination of precious metals in ores and rocks by thermal neutron activation/\gamma-spectrometry after preconcentration by nickel sulphide fire assay and coprecipitation with tellurium Type A1 Journal article
Year 1987 Publication Analytica chimica acta Abbreviated Journal Anal Chim Acta
Volume 196 Issue Pages 49-58
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) The six platinum group elements (Ru, Rh, Pd, Os, Ir and Pt) can be determined in geological samples down to the μg kg−1 level, by using nickel sulphide fire assay and neutron activation of the residue ramaining after dissolution of the nickel sulphide button in concentrated hydrochloric acid. Losses for the platinum group elements during this dissolution step are usually insignificant, except when the elements are present at ultra-trace levels. The can be recovered from the filtrate by coprecipitation with tellerium. The latter approach also permits determination of silver, which is significantly lost in the hydrochloric acid treatment (recovery <98% instead of typically ≈ 10%). The coprecipitation with tellurium considerably improves the results for gold (recovery ≈ 95% instead of typically 75%).
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos A1987K058900006 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2670; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.513 Times cited 49 Open Access
Notes Approved no
Call Number UA @ lucian @ c:irua:111403 Serial 670
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Author Verlinden, G.; Gijbels, R.; Geuens, I.
Title Chemical microcharacterization of ultrathin iodide conversion layers and adsorbed thiocyanate surface layers on silver halide microcrystals with time-of-flight SIMS Type A1 Journal article
Year 2002 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 8 Issue 3 Pages 216-226
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) The technique of imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS) and dual beam depth,profiling has been used to study the composition of the surface of tabular silver halide microcrystals. Analysis of individual microcrystals with a size well below 1 mum from a given emulsion is possible. The method is successfully applied for the characterization of silver halide microcrystals with subpercent global iodide concentrations confined in surface layers with a thickness below 5 nm. The developed TOF-SIMS analytical procedure is explicitly demonstrated for the molecular imaging of adsorbed thiocyanate layers (SCN) at crystal surfaces of individual crystals and for the differentiation of iodide conversion layers synthesized with KI and with AgI micrates (nanocrystals with a size between 10 and 50 nm). It can be concluded that TOF-SIMS as a microanalytical, surface-sensitive technique has some unique properties over other analytical techniques for the study of complex structured surface layers of silver halide microcrystals. This offers valuable information to support the synthesis of future photographic emulsions.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge, Mass. Editor
Language Wos 000179055900007 Publication Date 2002-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 1 Open Access
Notes Approved Most recent IF: 1.891; 2002 IF: 1.733
Call Number UA @ lucian @ c:irua:103876 Serial 349
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Author Ignatova, V.A.; Conard, T.; Möller, W.; Vandervorst, W.; Gijbels, R.
Title Depth profiling of ZrO2/SiO2/Si stacks : a TOF-SIMS and computer simulation study Type A1 Journal article
Year 2004 Publication Applied surface science Abbreviated Journal Appl Surf Sci
Volume 231/232 Issue Pages 603-608
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) This study is dedicated to a better understanding of the processes occurring under ion bombardment of ultra-thin ZrO2/SiO2/Si gate dielectric stacks. Complex-shaped depth profiles were obtained by using TOF-SIMS with dual beam (500 eV for sputtering and 10 keV for analysis) Ar+ ions. The SIMS intensities of all the elements depend critically on the amount of oxygen at any moment of the sputtering process. Increased intensity is observed at the surface and at the ZrO2/SiO2 interface. A long tail of the Zr signal is present in the Si substrate, even after the second (SiO2/Si) interface, and a double bump structure in the Zr-90 and ZrO dimer is observed, which is more pronounced with increasing thickness of the interfacial SiO2 layer. Computer simulations using the dynamic Monte Carlo code (TRIDYN) are performed in order to distinguish the ion bombardment-induced effects from changes in the ionization degree. The original code is extended with simple models for the ionization mechanism and for the molecular yield during sputtering. Oxygen preferential sputtering at the surface and ballistic transport of Zr towards and through the interface are clearly demonstrated, but there is also evidence that due to recoil implantation oxygen gets piled-up near the ZrO2/SiO2 interface. (C) 2004 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000222427700118 Publication Date 2004-05-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited 4 Open Access
Notes Approved Most recent IF: 3.387; 2004 IF: 1.497
Call Number UA @ lucian @ c:irua:51976 Serial 651
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Author Lenaerts, J.; van Vaeck, L.; Gijbels, R.
Title Secondary ion formation of low molecular weight organic dyes in time-of-flight static secondary ion mass spectrometry Type A1 Journal article
Year 2003 Publication Rapid communications in mass spectrometry Abbreviated Journal Rapid Commun Mass Sp
Volume 17 Issue 18 Pages 2115-2124
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Time-of-flight static secondary ion mass spectrometry (TOF-S-SIMS) was used to characterize thin layers of oxy- and thiocarbocyanine dyes on Ag and Si. Apart from adduct ions a variety of structural fragment ions were detected for which a fragmentation pattern is proposed. Peak assignments were confirmed by comparing spectra of dyes with very similar structures. All secondary ions were assigned with a mass accuracy better than 50 ppm. The intensity of molecular ions as well as fragment ions has been studied as a function of the type of organic dye, the substrate, the layer thickness and the type of primary ion. A large yield difference of two orders of magnitude was observed between the precursor ions of cationic carbocyanine dyes and the protonated molecules of the anionic dyes. Fragment ions, on the other hand, yielded similar intensities for both types of dye. As the dye layers deposited on an Ag substrate yielded higher secondary ion intensities than those deposited on a Si substrate, the Ag metal clearly acts as a promoting agent for secondary ion formation. The effect was more pronounced for precursor signals than for fragment ions. The promoting effect decreased as the deposited layer thickness of the organic dye layer was increased. Copyright (C) 2003 John Wiley Sons, Ltd.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000185230400014 Publication Date 2003-09-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0951-4198;1097-0231; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.998 Times cited 10 Open Access
Notes Approved Most recent IF: 1.998; 2003 IF: 2.789
Call Number UA @ lucian @ c:irua:104132 Serial 2958
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Author de Witte, H.; Conard, T.; Vandervorst, W.; Gijbels, R.
Title Ion-bombardment artifact in TOF-SIMS analysis of ZrO2/SiO2/Si stacks Type A1 Journal article
Year 2003 Publication Applied surface science Abbreviated Journal Appl Surf Sci
Volume 203 Issue Pages 523-526
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) We analyzed ultra-thin ZrO2/SiO2/Si gate dielectrics under post-deposition anneals in dry O-2 at temperatures from 500 to 700 degreesC. TOF-SIMS profiling of ZrO2/SiO2/Si stacks is hampered by many sputter induced artifacts. The depletion of oxygen leads to a decrease in SIMS intensities. However, preferential sputtering is accompanied by transport of the depleted species towards the surface. Due to recoil implantation oxygen gets piled-up near the ZrO2/SiO2 interface. Either normal or radiation-enhanced diffusion transports oxygen back to the surface. Simultaneously also segregation of zirconium towards and through the interface is observed, resulting in a large zirconium tail in the underlying silicon substrate. (C) 2002 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Elsevier science bv Place of Publication Amsterdam Editor
Language Wos 000180527300119 Publication Date 2002-12-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited 15 Open Access
Notes Approved Most recent IF: 3.387; 2003 IF: 1.284
Call Number UA @ lucian @ c:irua:51975 Serial 1743
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