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Condensed Matter Physics Commons

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Full-Text Articles in Condensed Matter Physics

Nuclear Forward-Scattering Of Synchrotron Radiation From Krypton: First Observation And Application To The Study Of Lattice Dynamics In Near-Monolayer Krypton-On-Graphite, David Eric Johnson Jul 1995

Nuclear Forward-Scattering Of Synchrotron Radiation From Krypton: First Observation And Application To The Study Of Lattice Dynamics In Near-Monolayer Krypton-On-Graphite, David Eric Johnson

Physics Theses & Dissertations

Since 1985 nuclear-resonant scattering, and in particular nuclear forward-scattering, of synchrotron radiation has been observed in a select few Mossbauer isotopes including: 57Fe, 119Sn, 169Tm. For the first time, nuclear forward-scattering from the 9.4 keV Mossbauer level in 83Kr has been observed. A large resonance effect, comparable to that in 57Fe, has been observed in a variety of systems containing Kr including bulk crystals and physisorbed Kr-on-exfoliated graphite. Previous nuclear-resonant scattering experiments using synchrotron radiation have consisted of demonstration experiments. Nuclear forward-scattering from Kr has been applied to study the lattice dynamics of near-monolayer Kr-on-graphite …


The Characterization Of The Radiative Energy Transfer Process Among Holmium(3+) Ions In Yttrium(3) Aluminum(5) Oxygen(12), Terri Lynn Lazarus Jan 1995

The Characterization Of The Radiative Energy Transfer Process Among Holmium(3+) Ions In Yttrium(3) Aluminum(5) Oxygen(12), Terri Lynn Lazarus

Dissertations, Theses, and Masters Projects

This research comprises a comprehensive spectroscopic study of the characteristics of the solid state crystal YAG (Yttrium Aluminum Garnet) singly doped with Ho (Holmium) ions. An important area of solid state laser crystal research is the determination and optimization of the processes within these laser crystals which lead to efficient laser action. In most laser crystals, there is a donor ion such as Tm (Thulium) and an acceptor ion such as Ho. The donor ion generally has greater absorption than that of the acceptor at the wavelength of the pump source. The donor ion can transfer this absorbed energy to …


First Principles Linear Response Calculations Of Lattice Dynamics, Cheng-Zhang Wang Jan 1995

First Principles Linear Response Calculations Of Lattice Dynamics, Cheng-Zhang Wang

Dissertations, Theses, and Masters Projects

First principles calculations, using the density-functional theory and particularly the local density approximation (LDA), have achieved remarkable success in studying the properties of solid state systems. Although the basic results of these calculations are the electronic structures (eigenvalues, eigenfunctions, etc.) and the total energy of ground state, many other related physical properties can be deduced from them by investigating their response under external perturbations. Using the linear response method with linearized-augmented-plane-wave (LAPW) basis, we have calculated lattice dynamical properties of important semiconductors CuCl, SiC and ferroelectric KNbO{dollar}\sb3.{dollar} CuCl is known to exhibit large anharmonic effects and possibly a complicated multi-well …


Compensation And Characterization Of Gallium Arsenide, Randy A. Roush Jan 1995

Compensation And Characterization Of Gallium Arsenide, Randy A. Roush

Electrical & Computer Engineering Theses & Dissertations

The properties of transition metals in gallium arsenide have been previously investigated extensively with respect to activation energies, but little effort has been made to correlate processing parameters with electronic characteristics. Diffusion of copper in gallium arsenide is of technological importance due to the development of GaAs:Cu bistable photoconductive devices. Several techniques are demonstrated in this work to develop and characterize compensated gallium arsenide wafers. The material is created by the thermal diffusion of copper into silicon-doped GaAs. Transition metals generally form deep and shallow acceptors in GaAs, and therefore compensation is possible by material processing such that the shallow …