Date of Award
2-1977
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Mechanical Engineering
First Advisor
Robert N. Blumenthal
Second Advisor
Martin A. Seitz
Third Advisor
R.A. Gaggioli
Fourth Advisor
R.F. Brebrick
Fifth Advisor
Walter Hirthe
Abstract
Doped cerium oxide has shown great promise as an electrolyte in high temperature fuel cells. However before its application is justified, a better understanding of the defect structure in doped cerium oxide is required. Cerium oxide has extensive solubility for aliovalent cations and exhibits a large non-stoichiometric region at elevated temperatures. Although there have been several defect structure analysis of both "pure" and doped cerium oxide, a combined analysis of electrical conductivity. ionic transference number and non-stoichiometry is not available.
In this investigation~ electrical conductivity of CaO and Y2O3 doped CeO2 is measured as a function of temperature and oxygen pressure. The ionic transference numbers of CaO doped CeO2 are measured using galvanic cells as a function of temperature and oxygen pressure. The results are analyzed in combination with non-stoichiometric data available, and the partial ionic and electronic conductivities are obtained as a function of temperature and non-stoichiometry.