Doctoral Dissertations

Gerald J. Roe

Abstract

"The iron-holmium phase diagram was investigated to determine the alloying behavior of these two metals and to determine the magnetic properties of some of the iron-holmium alloys which formed intermediate phases. The iron-holmium binary system was determined by three experimental techniques, differential thermal analysis (DTA), x-ray diffraction, and metallography. A phase diagram with three eutectic points and four intermediate phases was constructed from the experimental data. The two phases, Ho₆Fe₂₃ and Ho₂Fe₁₇, melted congruently at 1322⁰C and 1343⁰C respectively. HoFe₂ and HoFe₃ melted incongruently at 1288⁰C and 1293⁰C respectively. Neutron diffraction investigations were made on the intermediate phases Ho₆Fe₂₃ and HoFe₂ to obtain information on their magnetic structures. From the plots of magnetic ordering vs. temperature, the Curie temperature of Ho₆Fe₂₃ was placed at 500⁰K, and that of HoFe₂ at 600⁰K. Intensity calculations for the Ho₆Fe₂₃ data showed a ferrimagnetic structure with saturation moments of 2.25 and 9.3 µB for iron and holmium respectively. The magnetic and chemical cells of Ho₆Fe₂₃ were coincidental, while the magnetic cell of HoFe₂ was approximately four times larger than its chemical cell"--Abstract, page i.

Advisor(s)

O'Keefe, T. J. (Thomas J.)

Committee Member(s)

Danner, Horace P.
Weart, Harry W.
Leighly, Hollis P., 1923-2004
McDonald, H. O. (Hector O.)
James, William Joseph

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Metallurgical Engineering

Sponsor(s)

University of Missouri - Rolla. Graduate Center for Materials Research

Publisher

University of Missouri--Rolla

Publication Date

1969

Pagination

viii, 110 pages

Note about bibliography

Includes bibliographical references (pages 74-77).

Rights

© 1969 Gerald John Roe, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Holmium -- Magnetic propertiesIron alloys -- Magnetic propertiesPhase diagrams

Thesis Number

T 2230

Print OCLC #

6007115

Electronic OCLC #

806354272

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Metallurgy Commons

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