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West Virginia University

Theses/Dissertations

2000

Condensed matter physics

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Synthesis And Characterization Of Metal Oxide Nanoparticles, Heidi Jo Magnone Dec 2000

Synthesis And Characterization Of Metal Oxide Nanoparticles, Heidi Jo Magnone

Graduate Theses, Dissertations, and Problem Reports

Nanoparticles of CuO, Co3O4 and Mn5O 8 were prepared via sol-gel chemical routes. Thermal treatments of the gels were used to obtain particles of different sizes, as determined by the widths of the Bragg lines in x-ray diffraction. To prepare CuO nanoparticles, a Cu(OH)2 gel was first produced by reacting copper nitrate with sodium hydroxide, followed by annealing the gel at temperatures between 160°C to 1,000°C to produce particles in the 6 to 36 nm range. Nanoparticles of Co3O4 in the size range of 9 to 45 nm were prepared in an analogous manner by reacting cobalt nitrate and sodium …


Characterization Of A Novel Methyl Radical Source And Related Thin Film Growth Studies, Jeffrey Stephen Gold Dec 2000

Characterization Of A Novel Methyl Radical Source And Related Thin Film Growth Studies, Jeffrey Stephen Gold

Graduate Theses, Dissertations, and Problem Reports

An ultrahigh vacuum compatible methyl (CH3) radical source has been developed. The methyl radicals were generated by dc- and microwave-discharge processes in either of two ways. In the first, argon (Ar) or an Ar/Xe mixture was passed through the discharge to produce inert gas metastables that react with methane to produce the desired species. This was referred to as the indirect mode of operation. In the second or direct mode, an inert gas/methane mixture was passed directly through the discharge. The discharge/reaction products were sampled using a skimmer, and the resulting molecular beam was either characterized using a mass spectrometer …


Optical Characterization Of Compound Semiconductors Using Photoconductivity And Photoreflectance, Vladimir Alexandru Stoica Aug 2000

Optical Characterization Of Compound Semiconductors Using Photoconductivity And Photoreflectance, Vladimir Alexandru Stoica

Graduate Theses, Dissertations, and Problem Reports

Custom photoreflectance modulation spectroscopy and photoconductivity spectroscopy set-ups were constructed and used to characterize semiconductor materials. The ternary Cd1--xZnxTe compound was studied to achieve fine control over its composition to provide lattice-matched substrates for the growth of Hg1--xCdxTe which is used in infrared detectors. Photoreflectance spectroscopy, capable of accurate estimations of energy levels in semiconductors, was applied to determine composition in CdZnTe standards via band gap energy determinations. The excitonic contributions at room temperature were shown to be in agreement with literature data. The lack of lattice matched substrates for the growth of GaN is still providing material with considerable …


Ab Initio Studies Of Anisotropic Magnetism In Uranium And Cerium Monopnictides And Monochalcogenides, Eric Mason Collins May 2000

Ab Initio Studies Of Anisotropic Magnetism In Uranium And Cerium Monopnictides And Monochalcogenides, Eric Mason Collins

Graduate Theses, Dissertations, and Problem Reports

We have applied two ab initio based methods to investigate the origin in the electronic structure of the unusual magnetic behavior of the cerium and uranium monopnictides and monochalcogenides. First, we have carried out spin-polarized electronic structure calculations, based on the full potential linear muffin tin (FPLMTO) method, with spin polarization (orbital polarization only via spin-orbit coupling) and also with orbital polarization correction. Second, we have carried out ab initio based calculations synthesizing (1) a phenomenological theory of orbitally driven magnetism based on the Anderson and Kondo, lattice model which incorporates explicitly the hybridization induced and the Coulomb exchange interactions …