Doctoral Dissertations

Abstract

"The oxidation kinetics of polycrystalline SrTiO3 and LaCrO3 were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a reduced diffusion tail was observed in the TGA measurements. This observation can be interpreted as the initial diffusion along the boundaries and then spreading out into the lattice. The absence of the tail in the conductivity measurements is due to the high electron and hole mobility at the boundaries. The electrical conductivity and TGA results on Nb-doped LaCrO3 show that at low oxygen activity the material is a n-type conductor and as oxygen activity increases changes to a p-type conductor. This is consistent with a defect structure whose majority defects at low oxygen activity are electrons due to the donor; at high oxygen activity the increase of hole concentration due to the native oxygen excess nonstoichiometry of the oxide with its higher hole mobility results in p-type conduction. The experimental results also indicate that the electron mobility in this material is about 0.002 cm2/V-sec at 1200 °C""--Abstract, p. ii

Advisor(s)

Harlen U. Anderson

Committee Member(s)

P. Darrel Ownby
Don M. Sparlin
Robert E. Moore, 1930-2003
A. K. Rigler

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Comments

This work was funded by the Department of Energy.

Publisher

University of Missouri--Rolla

Publication Date

Spring 1986

Pagination

ix, 92 pages

Note about bibliography

Includes bibliographical references (pages 90-91).

Rights

© 1986 Chikung Jerry Yu, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 5363

Print OCLC #

15507960

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