Electronic band structure and optical properties of the cubic Sc, Y and La hybride systems

dc.contributor.author Peterman, Douglas
dc.contributor.department Physics and Astronomy
dc.date 2018-08-16T09:23:59.000
dc.date.accessioned 2020-07-02T05:56:18Z
dc.date.available 2020-07-02T05:56:18Z
dc.date.copyright Tue Jan 01 00:00:00 UTC 1980
dc.date.issued 1980
dc.description.abstract <p>Electronic band structure calculations are used to interpret the optical spectra of the cubic Sc, Y and La hydride systems. Self-consistent band calculations of ScH(,2) and YH(,2) are carried out using the Korringa-Kohn-Rostoker method. The respective joint densities of states are computed and compared to the dielectric functions determined from the optical measurements of Weaver, Rosei and Peterson. Additional calculations are performed in which the Fermi level or band gap energies are rigidly shifted by a small energy increment. These calculations are then used to simulate the derivative structure in thermomodulation spectra and relate the origin of experimental interband features to the calculated energy bands. While good systematic agreement is obtained for several spectral features, the origin of low-energy interband transitions in YH(,2) cannot be explained by these calculated bands. A lattice-size-dependent premature occupation of octahedral sites by hydrogen atoms in the fcc metal lattice is suggested to account for this discrepancy. Various non-self-consistent calculations are used to examine the effect of such a premature occupation. Measurements of the optical absorptivity of LaH(,x) with 1.6 < x < 2.9 are presented which, as expected, indicate a "more premature" occupation of the octahedral sites in the larger LaH(,2) lattice. These experimental results also suggest that, in contrast to recent calculations, LaH(,3) is a small-band-gap semiconductor;*DOE Report IS-T-899. This work was performed under Contract W-7405-eng-82 with the Department of Energy.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/6755/
dc.identifier.articleid 7754
dc.identifier.contextkey 6293364
dc.identifier.doi https://doi.org/10.31274/rtd-180813-3576
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/6755
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/79557
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/6755/r_8019657.pdf|||Sat Jan 15 01:27:55 UTC 2022
dc.subject.disciplines Condensed Matter Physics
dc.subject.keywords Physics
dc.subject.keywords Solid state physics
dc.title Electronic band structure and optical properties of the cubic Sc, Y and La hybride systems
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 4a05cd4d-8749-4cff-96b1-32eca381d930
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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