Masters Theses

Lih-da Hu

Abstract

"Undoped, semiconducting single, n-type, InSb crystals were used to study the different etching behavior of the inverse {111} planes, to determine the apparent electron number of InSb under anodic dissolution (which corresponds to the sum of the absolute values of the oxidation numbers) and to investigate whether or not the inverse {111} planes show potential differences. The In {111}, Sb {111[repeating]}, {110} and {100} faces were highly polished, etched and immersed in various acidic solutions. Several new etch patterns of the inverse {111} faces were observed in giving other possibilities to distinguish both of the planes. The significant differences in potentials between the inverse {111} faces are exhibited in some acidic solutions. The potential of Sb {111[repeating]} is always less noble that of In {111}. The addition of oxidizing or reducing agents does not shift the sequence in potentials of the inverse {111} faces within at least a certain range of current density. The apparent electron number of InSb dissolving anodically in acidic solutions is close to 6 at low current densities. The deviation from the value of 6, for InSb dissolving anodically in 2 N HCl at current densities higher than ~40 ma/cm², is found to be due to surface disintegration after a dark protective film (mainly Sb₄O₅Cl₂) is formed on the surface of the specimen. Sb particles, colloidal in origin and embedded in this corrosion product, are responsible for the dark color. It is also found that the dissolution potentials of the inverse {111} faces of InSb are much closer to that of metallic Sb than to metallic In, indicating that the latter undergoes a larger chemical change during the InSb formation than Sb. From the observed Tafel behavior and the calculated activation energies of InSb undergoing anodic dissolution in 2 N HCl, within the current density range of ~3 x 10⁻² to ~30 ma/cm², it is concluded that the rate determining step is a one electron discharge and is the same on all four low-indexed crystallographic planes"--Abstract, Pages ii-iii.

Advisor(s)

Straumanis, Martin E., 1898-1973

Committee Member(s)

James, William Joseph
Johnson, James W., 1930-2002

Department(s)

Chemical and Biochemical Engineering

Degree Name

M.S. in Chemical Engineering

Sponsor(s)

United States. Office of Naval Research

Publisher

University of Missouri--Rolla

Publication Date

1969

Pagination

xiv, 122 Pages

Note about bibliography

Includes bibliographical references (pages 89-93).

Rights

© 1969 Lih-da Hu, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

SemiconductorsIndium antimonide crystalsElectrolytic oxidation

Thesis Number

T 2279

Print OCLC #

6011716

Electronic OCLC #

846504167

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