Date of Award
Summer 1972
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Mechanical Engineering
First Advisor
Blumenthal, Robert N.
Second Advisor
Hirthe, Walter M.
Third Advisor
Seitz, Martin A.
Abstract
To date most physical property measurements on cerium dioxide (e.g., electrical conductivity, weight change, dielectric constant etc.) both at Marquette and elsewhere have been performed on sintered samples. These samples contain defects such as grain boundaries, pores, and surface defects which might alter the measured properties. As a result there exists a need for single crystals of an appropriate size and purity for physical characterization measurements. While there are single crystals of CeO2 available, they are at best a few millimeters on an edge and contain better than 100 ppm cation impurities. The literature indicates that there has been considerable success with the growth of other metal oxides such as AL203 and Sn02 by chemical transport techniques. Using chemical reactions involving the respective netal halides, single crystals as large as 5 grams and impurity levels below 10 ppm have been obtained. Calculations show the oxidation of CeCl3, CeBr3, and Cel3 to Ce02 to be thermodynamically possible and initial experiments show the following chemical reaction to be most favorable "formula". The change in standard Gibbs free energy for this reaction is found to decrease with increasing temperature and experiments show the reaction may be reversed at will thus enhancing thermodynamic control.
Recommended Citation
Marshall, Dennis L., "Chemical Vapor Transport of Cerium Dioxide" (1972). Master's Theses (1922-2009) Access restricted to Marquette Campus. 4769.
https://epublications.marquette.edu/theses/4769