Oxygen self-diffusion via a mobile intermediate species in rutile titania

Pangan-Okimoto, Kristine

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https://hdl.handle.net/2142/46803 Copy

Description

Title

Oxygen self-diffusion via a mobile intermediate species in rutile titania

Author(s)

Pangan-Okimoto, Kristine

Issue Date

2014-01-16T18:16:33Z

Director of Research (if dissertation) or Advisor (if thesis)

Seebauer, Edmund G.

Department of Study

Chemical and Biomolecular Engineering

Discipline

Chemical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Defect Engineering
• Titanium Dioxide (TiO2)
• Semiconductors

Abstract

Recent work in this laboratory has found that an atomically clean (110) surface on rutile titania allows for facile injection of a mobile oxygen intermediate other than the doubly-charged oxygen vacancy. Characteristic exponential tail profiles coupled with the observation of a positive oxygen partial pressure dependence on isotopic oxygen diffusion in rutile suggests that the observed mobile oxygen intermediate is a negatively charged oxygen interstitial (Oix-). Two modeling techniques are utilized to kinetically simulate the concentration profiles observed. Both models predict bulk isotopic oxygen diffusion that is highly dependent on the ability of the surface to inject and annihilate oxygen interstitials into the bulk. Additionally, modeling of the experimental profiles suggest that oxygen interstitials have equilibrium concentrations one to two orders of magnitude larger than that predicted by quantum calculations. Methods to effectively control the equilibrium concentration of oxygen interstitials via surface manipulation are suggested that may be utilized to effectively p-dope rutile titania.

Graduation Semester

2013-12

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http://hdl.handle.net/2142/46803

Copyright and License Information

Copyright 2013 Kristine Pangan-Okimoto

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