I. A Structural Investigation of the Mercury-Tin System. II. The Determination of the Crystal Structure of the Sigma Phase by Application of X-Ray Diffraction Methods to This Phase in the Iron-Chromium and Iron-Molybdenum Systems

Author: Bergman, B. Gunnar

Year: 1951

Degree: Dissertation (Ph.D.)

Advisor: Pauling, Linus

Committee Member: Unknown, Unknown

Option: Chemistry; Physics

DOI: 10.7907/1gn8-2a14

Abstract

A study of the mercury-tin system has been made by the application of thermal analysis and x-ray powder methods in order to determine whether four hypothetical intermetallic compounds of the compositions HgSn₃₅, HgSn₁₇, HgSn₁₁ and HgSn₈ proposed by Professor Linus Pauling, exist. The thermal analysis did not indicate the presence of these compounds in equilibrium with the liquid phase. By x-ray powder methods the occurrence of only two different phases was established, one of tetragonal structure and identical with that of white tin, and one of simple hexagonal structure as has been reported by previous workers. The four intermetallic compounds proposed by Professor Pauling do not seem to exist.

The structure of the sigma phase in the iron-chromium system at 46.5 at. % chromium content has been successfully determined by the application of x-ray diffraction methods. The structure is of a type that has not been observed earlier in intermetallic compounds.

The structure of the sigma phase in the iron-molybdenum system has also been investigated briefly and found to be of the same type as the iron-chromium sigma structure.

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