Doctoral Dissertations

Abstract

"The Ba2YCu3O7-x system was investigated using thermogravimetric, thermopower, and d.c. electrical conductivity techniques. The system was found to exhibit a semiconductor to metallic transition coincident with the documented orthorhombic to tetragonal phase transition. Conduction is accomplished in the semiconducting phase by an activated small hopping polaron mechanism. The oxide was observed to be a p-type semiconductor over the temperature and oxygen activity ranges studied.

The conductivity, carrier concentration, and mobility behaviors of the oxide are primarily functions of its oxygen content. All three properties exhibited only a slight temperature dependence. The carrier concentration is essentially constant at a given oxygen content. The carrier concentration ranged from about 0.5 x 1021/cm3 at 800°C and O = 6.3 to 6 x 1021/cm3 at 500°C and O = 6.95. Mobilities ranged from about 0.05 cm2/V sec. at 600°C and O = 6.4 to 0.5 at 800°C and O = 6.7"--Abstract, page ii.

Advisor(s)

Anderson, H. U. (Harlan U.)

Committee Member(s)

Moore, Robert E., 1930-2003
Ownby, P. D.
Guha, Jyoti, P.
Sparlin, Don M.
Pringle, Oran Allan

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Sponsor(s)

United States. Department of Energy

Publisher

University of Missouri--Rolla

Publication Date

Spring 1989

Pagination

viii, 122 pages

Note about bibliography

Includes bibliographic references (pages 104-114).

Rights

© 1989 C. John Brannon, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Thesis Number

T 5863

Print OCLC #

20900371

Electronic OCLC #

1091902652

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