rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Secondary ion emission from "super-efficient" events
    sub title: prospects for surface mass spectrometry
  name:
    name part: Rickman, Richard Dale
    name part: 1962-
    role:
      role term: creator
  name:
    name part: Schweikert, Emile A.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2004
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: Some collision cascades, induced by keV polyatomic projectiles, result in the emission of multiple secondary ions. Such co-emissions imply that the ejecta originate from molecules co-located within the nano-volume perturbed by a single projectile impact. The relevance for the chemical analysis of nano-domains depends on the effectiveness of the projectile to cause co-emission of two or more secondary ions. This research examines how projectile characteristics, i.e. the energy and number of constituent atoms in the projectile, influence multiple secondary ion emission, or "superefficient" events. In addition we examine the relevance of this technique for nanostructure investigation. Yields have been measured for multi-ion emission events as a function of projectile characteristics. The data show that some collision cascades are "superefficient". For example, in a four-ion emission event, the yield for the phenylalanine quasi-molecular ion is two orders of magnitude larger from Au₄+ impacts than from equal velocity Au+ projectiles. Yields for the co-emission of two phenylalanine quasi-molecular ions from "super-efficient" events have been measured. This case is particularly productive in that the detection of two analytically significant ions is recorded from a single event. Large increases (one to two orders of magnitude) in co-emitted ion yields were observed with increasing projectile energy and complexity. Correlation coefficients were calculated for the co-emission of two Ph ions, their behavior suggests differences in emission pathways for bombardment by atomic and polyatomic projectiles. Finally, we use this methodology to investigate surface structural effects on the occurrence of "super-efficient" events. The results indicate that it is possible to distinguish between two phases of a chemical compound although the stoichiometry remains the same. These results confirm previous predictions concerning the chemical nature of these "super-efficient" events. Also s…
  note: by Richard Dale Rickman.
  note: "Major Subject: Chemistry"
  note: Title from author supplied metadata (record created on Nov. 30, 2005.)
  note: Vita.
  note: Abstract.
  note: Electronic resource.
  note: System requirements: Adobe Acrobat Reader.
  note: Ph. D. Texas A&M University 2004
  note: Includes bibliographical references.
  note: Text (Dissertation).
  subject:
    topic: Major chemistry
  subject:
    topic: SIMS
  subject:
    topic: Event-by-Event
  subject:
    topic: Polyatomic Projectiles
  subject:
    topic: Surface Characterization
  subject:
    topic: Multiple Ion Emission Events
  identifier: http://hdl.handle.net/1969.1/520
  record info:
    record content source: TXA
    record creation date: 110303
    record change date: 20151202115555.0
    record identifier: in00002644978