Formation, trapping, and ejection of radiolytic O2 from ion-irradiated water ice studied by sputter depth profiling

2009 ◽  
Vol 130 (13) ◽  
pp. 134704 ◽  
Author(s):  
B. D. Teolis ◽  
J. Shi ◽  
R. A. Baragiola
Keyword(s):  
Author(s):  
M.P. Thomas ◽  
A.R. Waugh ◽  
M.J. Southon ◽  
Brian Ralph

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.


Author(s):  
Mark Denker ◽  
Jennifer Wall ◽  
Mark Ray ◽  
Richard Linton

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.


2017 ◽  
Vol 26 (1) ◽  
pp. 53-68
Author(s):  
Mark Byron

Scholarly research over the last twenty years has marked a profound shift in the understanding of Beckett's sources, his methods of composition, and his attitudes towards citation and allusion in manuscript documents and published texts. Such landmark studies as James Knowlson's biography, Damned to Fame (1996), and John Pilling's edition of the Dream Notebook (1999), and the availability of primary documents such as Beckett's reading notes at Reading and Trinity libraries, opened the way for a generation of work rethinking Beckett's textual habitus. Given this profound reappraisal of Beckett's material processes of composition, this paper seeks to show that Beckett's late prose work, Worstward Ho, represents a profound mediation on writing, self-citation, and habits of allusion to the literary canon. In its epic gestures, it reorients the heavenly aspiration of Dante's Commedia earthwards, invoking instead the language of agriculture, geology and masonry in the process of creating and decreating its imaginative space. Beckett's earthy epic invokes and erodes the first principles of narrative by way of philology as well as by means of deft reference to literary texts and images preoccupied with land, farming, and geological formations. This process is described in the word corrasion, a geological term referring to the erosion of rock by various forms of water, ice, snow and moraine. Textual excursions into philology in Worstward Ho also unearth the strata comprising Beckett's corpus (in particular Imagination Dead Imagine, The Lost Ones, and Ill Seen Ill Said), as well as the rock or canon upon which his own literary production is built. A close reading of Worstward Ho turns up a number of shrewd allusions to the King James Bible and Thomas Browne, as one might expect, but also perhaps surprisingly sustained affinities with the literary sensibilities of Alexander Pope and the poetry of S. T. Coleridge. The more one digs, the more Beckett's ‘little epic’ seems to become one of earthworks, bits of pipe, and masonry, a site and record of literary sedimentation.


2009 ◽  
Vol 13 (4) ◽  
pp. 210-218 ◽  
Author(s):  
Volker Schöffl ◽  
Isabelle Schöffl ◽  
Ulrich Schwarz ◽  
Friedrich Hennig ◽  
Thomas Küpper

2013 ◽  
Vol 47 ◽  
pp. 167-178 ◽  
Author(s):  
M. P. Andreev

Lichen flora and vegetation in the vicinity of the Russian base «Molodyozhnaya» (Enderby Land, Antarctica) were investigated in 2010–2011 in details for the first time. About 500 specimens were collected in 100 localities in all available ecotopes. The lichen flora is the richest in the region and numbers 39 species (21 genera, 11 families). The studied vegetation is very poor and sparse, but typical for coastal oases of the Antarctic continent. The poorness is caused by the extremely harsh climate conditions, insufficient availability of liquid water, ice-free land, and high insolation levels. The dominant and most common lichens are Rinodina olivaceobrunnea, Amandinea punctata, Candelariella flava, Physcia caesia, Caloplaca tominii, Lecanora expectans, Caloplaca ammiospila, Lecidea cancriformis, Pseudephebe minuscula, Lecidella siplei, Umbilicaria decussata, Buellia frigida, Lecanora fuscobrunnea, Usnea sphacelata, Lepraria and Buellia spp.


Author(s):  
Wentao Qin ◽  
Dorai Iyer ◽  
Jim Morgan ◽  
Carroll Casteel ◽  
Robert Watkins ◽  
...  

Abstract Ni(5 at.%Pt ) films were silicided at a temperature below 400 °C and at 550 °C. The two silicidation temperatures had produced different responses to the subsequent metal etch. Catastrophic removal of the silicide was seen with the low silicidation temperature, while the desired etch selectivity was achieved with the high silicidation temperature. The surface microstructures developed were characterized with TEM and Auger depth profiling. The data correlate with both silicidation temperatures and ultimately the difference in the response to the metal etch. With the high silicidation temperature, there existed a thin Si-oxide film that was close to the surface and embedded with particles which contain metals. This thin film is expected to contribute significantly to the desired etch selectivity. The formation of this layer is interpreted thermodynamically.


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