Graduate Thesis Or Dissertation

 

Characterization of CoGe Thin Films and Powders Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/wp988p24d

Descriptions

Attribute NameValues
Creator
Abstract
  • Cobalt germanides have been widely studied as semiconductor contact materials, but recent theoretical studies suggest that they may also be excellent catalysts for methane steam reforming with stabilities and activities comparable to noble metal catalysts. In order to study the catalytic activity of cobalt germanides, it is critical to first characterize their bulk and surface properties. Sputter deposited CoGe alloy thin films and powders were characterized after post-deposition annealing in high vacuum, argon, and air up to 1000˚C. A range of bulk and surface properties were characterized in order assess CoGe thermal and chemical stability, which may provide insight on its suitability as a methane reforming catalyst. Ge is preferentially oxidized in the CoGe alloy. Three different Ge-loss events via GeO desorption were observed, including surface GeO desorption starting at ~350 °C, loss of excess Ge and O from the bulk driven by crystallization starting at ~650-700 °C, and reaction of trace amounts of ambient oxygen at temperatures ≥800 °C to form GeO at the surface, which desorbs. More research is needed to determine if Ge-depletion under methane steam reforming conditions will make cobalt germanides unsuitable as catalysts, though recent near-ambient pressure X-ray photoelectron spectroscopy studies under steam reforming conditions suggest that Ge oxidation is unlikely.
License
Resource Type
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Julie Kurtz(julie.kurtz@oregonstate.edu) on 2017-01-03T20:52:12Z (GMT) No. of bitstreams: 1 PfauAndrewJ2016.pdf: 4994633 bytes, checksum: fa1662d11943099d2d6ce6679d47b797 (MD5)
  • description.provenance : Submitted by Andrew Pfau (pfaua@oregonstate.edu) on 2016-12-31T17:15:19Z No. of bitstreams: 1 PfauAndrewJ2016.pdf: 4994633 bytes, checksum: fa1662d11943099d2d6ce6679d47b797 (MD5)
  • description.provenance : Made available in DSpace on 2017-01-04T23:06:52Z (GMT). No. of bitstreams: 1 PfauAndrewJ2016.pdf: 4994633 bytes, checksum: fa1662d11943099d2d6ce6679d47b797 (MD5) Previous issue date: 2016-12-06
  • description.provenance : Approved for entry into archive by Laura Wilson(laura.wilson@oregonstate.edu) on 2017-01-04T23:06:52Z (GMT) No. of bitstreams: 1 PfauAndrewJ2016.pdf: 4994633 bytes, checksum: fa1662d11943099d2d6ce6679d47b797 (MD5)
Embargo date range
  • 2017-08-22 to 2018-02-13

Relationships

Parents:

This work has no parents.

In Collection:

Items