Doctoral Dissertations

Author

Weiming Zhang

Abstract

"Ferroelectric emission (FE) was discovered at CERN in 1988. However, a diverse array of results and explanations concerning FE have appeared. This dissertation focused on understanding the influence of material properties and external parameters on this complex process. The sample preparation, pulse generator and other experimental techniques are described.

Plasma emission (PE), FE and mixed PE and FE were observed and described. The field enhancement at the electrode-dielectric-vacuum triple point was suggested to be the basis for PE. An apparent delay time, instability, visible light generation and strong electrode erosion are features of PE. Comparatively, FE does not require an extraction field, exhibits no apparent delay time and a relatively stable emission, and generates either no or a very weak light signal. A direct relationship between the switching current and emission current exists for the FE.

Different FE characteristics of antiferroelectric PLZT 2/95/5, "normal" ferroelectric PLZT 8/65/35 and nonferroelectric PLZT 15/65/35 were described. The strong relationship between the emission and switching current was demonstrated. Repeatable emission is exhibited by 2/95/5, which can also be pulsed at high frequency due to its fast antiferroelectric ⬄ ferroelectric phase transition. The strong degradation of FE from 8/65/35 was attributed to decrease in the remanent polarization. While no emission signal was detected from 15/65/35, which can be interpreted as an additional evidence that electron emission from the above two PLZT was indeed FE process.

Based on the field and domain switching distribution model, sample geometry effect on FE was predicted, and verified using the results from different groups. Electron emission energy distribution of PLZT 8/65/35 showed a very narrow energy distribution (FWHM ≈ 10 eV to 20 eV), and the emission energy was on the order of the applied pulse potential.

The possible application of FE for emissive flat panel displays was discussed compared to the mature technology based on field emitters"--Abstract, page iii.

Advisor(s)

Huebner, Wayne

Committee Member(s)

Anderson, H. U. (Harlan U.)
Moore, Robert E., 1930-2003
Day, D. E.
Waddill, George Daniel

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Publisher

University of Missouri--Rolla

Publication Date

Fall 1997

Pagination

xiv, 170 pages

Note about bibliography

Includes bibliographical references (pages 163-169).

Rights

© 1997 Weiming Zhang, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Thesis Number

T 7367

Print OCLC #

39244190

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