THE STRUCTURAL AND VIBRATIONAL PROPERTIES OF AMORPHOUS AND CRYSTALLINE GROUP V ELEMENTS
- Author
- SHANABROOK, BENJAMIN VICTOR
- Physical Description
- 134 pages
- Additional Creators
- Pennsylvania State University
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- Summary
- The structural and vibrational properties of crystalline and amorphous (a-) group V elements have been examined. First and second order Raman scattering measurements of orthorhombic (o-)P and o-As have been performed. A scaling relation between the k = 0 phonon frequencies of o-As and o-P as well as a Born model calculation have indicated that the near-neighbor force constants are larger in o-P. The excellent agreement between the second order Raman spectrum and a theoretical calculation of o-As has suggested the dominance of overtone scattering. Furthermore, the second order Raman spectra suggest that greater phonon dispersion exists in o-As relative to o-P. These studies suggest that a larger contribution of covalent bonding exists in o-P. Similarities between the Raman spectra of o-P and a-P have been observed. These may result as a consequence of similar near-neighbor bonding interactions.
In contrast to earlier suggestions, the structural studies of a-P samples have indicated that highly variable intermediate range structural correlations may exist in an amorphous network. Furthermore, these correlations appear related to displacement induced polarizability correlations probed by Raman scattering. This suggested interrelationship is in qualitative accord with recent theoretical suggestions of Martin and Galeener. In addition, these studies also suggest that the bonding coordination defect models of Pollard and Joannopoulos are not appropriate for a-P. In contrast to the random network model, a distorted layerlike model appears to be a better structural prototype of a-P. - Other Subject(s)
- Dissertation Note
- Ph.D. The Pennsylvania State University 1981.
- Note
- Source: Dissertation Abstracts International, Volume: 42-05, Section: B, page: 1939.
- Part Of
- Dissertation Abstracts International
42-05B
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