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Munster, Germany

Kilner J.A.,Imperial College London | Skinner S.J.,Imperial College London | Brongersma H.H.,Imperial College London | Brongersma H.H.,TU Eindhoven | Brongersma H.H.,ION TOF GmbH
Journal of Solid State Electrochemistry | Year: 2011

The determination of the mass transport kinetics of oxide materials for use in electrochemical systems such as fuel cells, sensors and oxygen separators is a significant challenge. Several techniques have been proposed to derive these data experimentally with only the oxygen isotope exchange depth profile technique coupled with secondary ion mass spectrometry (SIMS) providing a direct measure of these kinetic parameters. Whilst this allows kinetic information to be obtained, there is a lack of knowledge of the surface chemistry of these complex processes. The advent of low-energy ion scattering (LEIS) now offers the opportunity of correlating exchange kinetics with chemical processes at materials atomic surfaces, giving unprecedented levels of information on electrochemical systems with isotopic discrimination. Here, the challenges of these techniques, including sample preparation, are discussed and the advantages of the combined approach of SIMS and LEIS illustrated with reference to key literature data. © 2011 Springer-Verlag.

Sjovall P.,SP Technical Research Institute of Sweden | Rading D.,ION TOF GmbH | Ray S.,National Physical Laboratory United Kingdom | Yang L.,National Physical Laboratory United Kingdom | Shard A.G.,National Physical Laboratory United Kingdom
Journal of Physical Chemistry B | Year: 2010

We demonstrate two methods to improve the quality of organic depth profiling by C60 sputtering using multilayered reference samples as part of a VAMAS (Versailles project on Advanced Materials and Standards) interlaboratory study. Sample cooling was shown previously to be useful in extending the useful depth over which organic materials can be profiled. We reinforce these findings and demonstrate that cooling results in a lower initial sputtering yield to approximately -40 °C, but the improvement in useful profiling depth continues as the sample is cooled further, even though there is no further reduction in the initial sputtering yield. We report, for the first time, the use of sample rotation in organic depth profiling and demonstrate that the initial sputtering yield at room temperature is maintained throughout the depth of the samples used in this study. Useful profiling depth and good depth resolution are both associated with a constant sputtering yield. The fact that rotation results in the maintenance of depth resolution underlines the fact that depth resolution is often limited by the development of ion-beam-induced topography. Constant sputtering yield results in a constant secondary-ion yield, after transient processes have occurred, and this allows simple quantification methods to be applied to organic depth profiling data. © 2010 American Chemical Society.

A method is used in a time-of-flight mass spectrometer for analysis of a first pulsed ion beam, the ions of which are disposed along the pulse direction, separated with respect to their ion masses. The ions of at least one individual predetermined ion mass or of at least one predetermined range of ion masses can be decoupled from the first pulsed ion beam, as at least one decoupled ion beam, and the first ion beam and the at least one decoupled ion beam are analyzed.

The invention relates to a mass spectrometer comprising an ion source for producing a primary ion beam, which has a heatable ion emitter coated by a liquid metal layer essentially comprised of pure metallic Bismuth or of a low-melting-point alloy containing, in essence, Bismuth. A Bismuth ion mixed beam can be emitted by the ion emitter under the influence of an electric field. From the Bismuth ion mixed beam, one of a number of Bismuth ion types whose mass is a multiple of monatomic singly or multiply charged Bismuth ions Bi

A liquid metal ion source for use in an ion mass spectrometric analysis method contains, on the one hand, a first metal with an atomic weight 190 U and, on the other hand, another metal with an atomic weight 90 U. One of the two types of ions are filtered out alternately from the primary ion beam and directed onto the target as a mass-pure primary ion beam.

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