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Full-Text Articles in Condensed Matter Physics
Development Of Co2 Laser-Heating For The Study Of Wide Band Gap Oxide Materials, Christian Matthew Childs
Development Of Co2 Laser-Heating For The Study Of Wide Band Gap Oxide Materials, Christian Matthew Childs
UNLV Theses, Dissertations, Professional Papers, and Capstones
The ability to access a vast region of the pressure-temperature landscape using energy density tuning enables exotic states of matter to be probed. A well documented method for such exploration, under static conditions, is the use of the laser-heated diamond anvil cell (LH-DAC), accessing a combination of high pressure (>300 GPa) and high temperature (>5000 K). This thesis presents our development of direct CO2 laser heating techniques to study a series of wide band gap insulators, La2Sn2O7, ZrO2, and CeO2, under high pressure conditions. The lasing frequency of CO2 lasers is such that these wide band gap materials …
High-Pressure High-Temperature Exploration Of Phase Boundaries Using Raman Spectroscopy, Jasmine Kashmir Hinton
High-Pressure High-Temperature Exploration Of Phase Boundaries Using Raman Spectroscopy, Jasmine Kashmir Hinton
UNLV Theses, Dissertations, Professional Papers, and Capstones
Metastability of states can provide interesting properties that may not be readily accessible in a material’s ground state. Many materials show high levels of polymorphism, indicating a rich energy landscape and a potential for metastable states. Melt crystallization techniques provide a potential route to these states. We use a resistively heated diamond anvil cell (DAC) with fine control of a system’s pressure and temperature to explore these systems. Raman spectroscopy is used to track subtle structural changes across phase boundaries. Organic systems, such as glycine and aspirin, were our initial interest due to their high polymorphism and reported low melting …
Spectroscopic Studies Of Melamine At High Pressure, Martin Donald Galley
Spectroscopic Studies Of Melamine At High Pressure, Martin Donald Galley
UNLV Theses, Dissertations, Professional Papers, and Capstones
We have performed mid- and far- Infra Red (IR) absorption, Raman spectroscopy, and angular dispersive x-ray diffraction (XRD) studies on melamine under high pressure and room temperature. We have verified the presence of two prior reported phase transitions, the first between 1-2 GPa, and the second between 7-9 GPa. We have also found evidence of a third unreported phase transition between 14-16 GPa, during which, there was a sudden disappearance of all low energy peaks (-1 ) in both the Raman and IR spectra. The far-IR peak movement experiences a discontinuity as the rate of peak movement suddenly changes. …