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

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.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Pangan-Okimoto, Kristine

Contributors dc:contributor

• Seebauer, Edmund G.

• Defect Engineering
• Titanium Dioxide (TiO2)
• Semiconductors

Statement dc:rights

• Copyright 2013 Kristine Pangan-Okimoto

Language dc:language

en

Handle dc:identifier

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

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/46803