Sponsor
Portland State University. Department of Physics
Date of Publication
8-30-1972
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Physics
Department
Physics
Language
English
Subjects
Mössbauer effect -- Measurement, Chromium
DOI
10.15760/etd.1577
Physical Description
1 online resource (viii, 55 p.)
Abstract
Precision measurements of the Mossbauer fraction of Fe57 in chromium were made using the black absorber technique over a range of temperatures from 78K to 792K. Because of uncertainty in corrections at high temperatures, only the data collected from 78K to 600K was used in analyzing the results.
The f values were analyzed in terms of a Debye approximmation. This analysis of the data yielded a theoretical fit which was based on two adjustable parameters (a Debye temperature of 438K and an anharmonicity parameter of 2 x 10-4K-1).
The f measurements were also analyzed using a theory proposed by Mannheim in 1968. Two different phonon density of states functions (Feldman, Muhlestein) were applied to Mannheim’s theory, and the resulting theoretical fits to experimental values showed a decrease in the force constant as a result of introducing an impurity into the chromium. Feldman’s phonon spectrum yielded a force constant ratio of 1.30±.07 and an anharmoncity parameter of ℇ=2.5(±.5) x 10-4K-1.
Rights
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Persistent Identifier
http://archives.pdx.edu/ds/psu/10792
Recommended Citation
Brace, B. Frederick Jr., "Measurements of the Mössbauer Fraction in Chromium" (1972). Dissertations and Theses. Paper 1578.
https://doi.org/10.15760/etd.1577