Ionic Liquids in Vacuo:  Analysis of Liquid Surfaces Using Ultra-High-Vacuum Techniques

Langmuir ◽  
2006 ◽  
Vol 22 (22) ◽  
pp. 9386-9392 ◽  
Author(s):  
Emily F. Smith ◽  
Frank J. M. Rutten ◽  
Ignacio J. Villar-Garcia ◽  
David Briggs ◽  
Peter Licence
Keyword(s):  
Ionic Liquids ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Liquid Surfaces

Ionic Liquids Studied at Ultra-High Vacuum

2012 ◽  
pp. 251-282
Author(s):  
Kevin R. J. Lovelock ◽  
Peter Licence
Keyword(s):  
Ionic Liquids ◽  
High Vacuum ◽  
Ultra High Vacuum

New Preparation Method For Liquid Alloy Surfaces and Their Characterization by Electron Spectroscopy

1986 ◽  
Vol 83 ◽  
Author(s):  
G. Indlekofer ◽  
P. Oelhafen ◽  
H.- J. Güntherodt
Keyword(s):  
Photoelectron Spectroscopy ◽  
Liquid State ◽  
Electron Spectroscopy ◽  
Surface Composition ◽  
Liquid Metals ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Valence Electron Structure ◽  
Composition Segregation ◽  
Liquid Surfaces

ABSTRACTSurface investigations of liquid metals in ultra-high vacuum are scarce as compared with solid state studies, mainly because of experimental difficulties of preparing atomically clean liquid surfaces. A new technique has been developed in order to prepare clean liquid metal surfaces. According to the characterization with electron spectroscopy it proved to be an effective way to obtain high purity liquid surfaces and hence offers the possibility to study a variety of metals and alloys in the liquid state.Information about the surface composition, segregation properties and its purity in the liquid state and the valence electron structure has been obtained by X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS, respectively). Exciting new insights in the electronic structure of various liquid alloys such as Au-Si, Cu-Sn, Ga-Sn and TI-Bi have been obtained from these measurements.

Tribological investigations of ionic liquids in ultra-high vacuum environment

2013 ◽  
Vol 26 (7-8) ◽  
pp. 514-524 ◽  
Author(s):  
Vladimir Totolin ◽  
Marcello Conte ◽  
Edurne Berriozábal ◽  
Francesco Pagano ◽  
Ichiro Minami ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Vacuum Environment

Evaluation of Vapor Pressure and Ultra-High Vacuum Tribological Properties of Ionic Liquids

2011 ◽  
Vol 54 (6) ◽  
pp. 911-919 ◽  
Author(s):  
Kenneth W. Street ◽  
Wilfredo Morales ◽  
Victor R. Koch ◽  
Daniel J. Valco ◽  
Ryan M. Richard ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Vapor Pressure ◽  
Tribological Properties ◽  
High Vacuum ◽  
Ultra High Vacuum

scholarly journals Evaluation of Vapor Pressure and Ultra-High Vacuum Tribological Properties of Ionic Liquids (2) Mixtures and Additives

2008 ◽  
Author(s):  
Wilfredo Morales ◽  
Kenneth W. Street ◽  
Victor R. Koch ◽  
Ryan M. Richard
Keyword(s):  
Ionic Liquids ◽  
Vapor Pressure ◽  
Tribological Properties ◽  
High Vacuum ◽  
Degradation Pathway ◽  
Ultra High Vacuum ◽  
Vapor Pressures ◽  
Ambient Conditions ◽  
Raman Analysis ◽  
Vapor Pressure Measurements

Ionic liquids are salts, many of which are typically viscous fluids at room temperature. The fluids are characterized by negligible vapor pressures under ambient conditions. These properties have led us to study the effectiveness of ionic liquids containing both organic cations and anions for use as space lubricants. In the previous paper we have measured the vapor pressure and some tribological properties of two distinct ionic liquids under simulated space conditions. In this paper we will present vapor pressure measurements for two new ionic liquids and friction coefficient data for boundary lubrication conditions in a spiral orbit tribometer using stainless steel tribocouples. In addition we present the first tribological data on mixed ionic liquids and an ionic liquid additive. Post mortem infrared and Raman analysis of the balls and races indicates the major degradation pathway for these two organic ionic liquids is similar to those of other carbon based lubricants, i.e. deterioration of the organic structure into amorphous graphitic carbon. The coefficients of friction and lifetimes of these lubricants are comparable to or exceed these properties for several commonly used space oils.

Thin Pyrolytic Graphite Films for Electron Microscope Substrates

1971 ◽  
Vol 29 ◽  
pp. 226-227 ◽  
Author(s):  
George H. N. Riddle ◽  
Benjamin M. Siegel
Keyword(s):  
Vacuum Chamber ◽  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Graphite Substrate ◽  
Nickel Substrate ◽  
Routine Procedure ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A routine procedure for growing very thin graphite substrate films has been developed. The films are grown pyrolytically in an ultra-high vacuum chamber by exposing (111) epitaxial nickel films to carbon monoxide gas. The nickel serves as a catalyst for the disproportionation of CO through the reaction 2C0 → C + CO2. The nickel catalyst is prepared by evaporation onto artificial mica at 400°C and annealing for 1/2 hour at 600°C in vacuum. Exposure of the annealed nickel to 1 torr CO for 3 hours at 500°C results in the growth of very thin continuous graphite films. The graphite is stripped from its nickel substrate in acid and mounted on holey formvar support films for use as specimen substrates.The graphite films, self-supporting over formvar holes up to five microns in diameter, have been studied by bright and dark field electron microscopy, by electron diffraction, and have been shadowed to reveal their topography and thickness. The films consist of individual crystallites typically a micron across with their basal planes parallel to the surface but oriented in different, apparently random directions about the normal to the basal plane.

A High Voltage Electron Microscopy Study of Sub-Oxide Formation in Vanadium

1971 ◽  
Vol 29 ◽  
pp. 212-213
Author(s):  
R. H. Geiss ◽  
R. L. Ladd ◽  
K. R. Lawless
Keyword(s):  
High Vacuum ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Ultra High Vacuum ◽  
Pure Oxygen ◽  
Pressure Oxidation ◽  
High Voltage Electron Microscopy ◽  
Oxidation Study ◽  
Voltage Electron ◽  
Good Agreement

Detailed electron microscope and diffraction studies of the sub-oxides of vanadium have been reported by Cambini and co-workers, and an oxidation study, possibly complicated by carbon and/or nitrogen, has been published by Edington and Smallman. The results reported by these different authors are not in good agreement. For this study, high purity polycrystalline vanadium samples were electrochemically thinned in a dual jet polisher using a solution of 20% H2SO4, 80% CH3OH, and then oxidized in an ion-pumped ultra-high vacuum reactor system using spectroscopically pure oxygen. Samples were oxidized at 350°C and 100μ oxygen pressure for periods of 30,60,90 and 160 minutes. Since our primary interest is in the mechanism of the low pressure oxidation process, the oxidized samples were cooled rapidly and not homogenized. The specimens were then examined in the HVEM at voltages up to 500 kV, the higher voltages being necessary to examine thick sections for which the oxidation behavior was more characteristic of the bulk.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

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