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- Aragonite; Barium Carbonate; Carbonates; High pressure (Science); Phase transformations (Statistical physics) (1)
- Crystal lattices; Raman spectroscopy; Spinel group (1)
- Crystalline structures (1)
- Crystallography (1)
- Deformation (1)
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- Elastic plastic self consistent (EPSC) model (1)
- Europium (1)
- Fayalite (1)
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- High pressure (Science) — Research (1)
- High pressure crystallography (1)
- High pressures (1)
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- Igneous rocks — Inclusions; Rock deformation; Rock mechanics; South Africa – Jagersfontein Mine; Strains and stresses (1)
- Magnetism (1)
- Mantle (1)
- Mineral properties (1)
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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Correlation Between Grain Dislocation Density And Orientation For Naturally Deformed Mantle Xenolith From Jagersfontein Mine, Quinton Guerrero, Quinlan Smith
Correlation Between Grain Dislocation Density And Orientation For Naturally Deformed Mantle Xenolith From Jagersfontein Mine, Quinton Guerrero, Quinlan Smith
Undergraduate Research Opportunities Program (UROP)
Determining the reaction of poly-crystalline structures to induced stress is an extremely difficult problem in contemporary engineering and geology. The main challenge lies in the inhomogeneity of the grains inside of the poly-crystalline structures. To predict the response of a certain polycrystalline structure to a specific stress, you must resort to one of two views on grain interaction, an orientation or propagation based model. For every material there may be certain correlations between the prediction model used and the actual deformation that occurred. Our work centers around describing the correlation of these prediction models with a sample of naturally deformed …
High Pressure Structural Studies On Baco3 Up To 20 Gpa, Justine Carryer, Ravhi S. Kumar
High Pressure Structural Studies On Baco3 Up To 20 Gpa, Justine Carryer, Ravhi S. Kumar
Undergraduate Research Opportunities Program (UROP)
Carbonate compounds are thought to make up a minor portion of the Earth's upper mantel. Shock heating of the surfaces of carbonate rocks, as in the instance of a meteor impact, has the potential to affect CO2 concentrations in the Earth's atmosphere. The bulkmodulus of carbonate materials is directly proportional to the rate of devolatilization under these conditions [1]. The interest in Barium Carbonate (BaCO3) specifically is motivated by its structural proximity to aragonite carbonates. Crystalline phase transitions occur in aragonite under extreme conditions that are difficult to maintain in a laboratory; BaC03 is isostructural with aragonite and therefore is …
Investigation Of Raman Active Modes Of Mgxzn1-Xcr2o4, Nichollas Macholl, Tyler Mosher
Investigation Of Raman Active Modes Of Mgxzn1-Xcr2o4, Nichollas Macholl, Tyler Mosher
Undergraduate Research Opportunities Program (UROP)
Using Raman spectroscopy, vibrational modes of the spinel structure MgxZn1-xCr2O4 were experimentally examined. The spinel compounds were synthesized by producing solid solutions via combustion method, of MgxZn1-xCr2O4 in the range x=0 to x=1 in 0.1 intervals. The purpose of which was to experimentally verify gradual shifts of Raman peaks as the samples transitioned between the two different compounds and gain information about the dependencies of the lattice vibrations on the tetrahedral and octahedral cations. X-ray diffraction was also used to verify spinel structure, and track the changes in lattice parameter of the samples.
Determination Of Olivine Orientation Dependence Through Raman Spectroscopy, Alexandra J. Leandre, Joseph Lussier, Brittany Morgan, Michael Rodriguez
Determination Of Olivine Orientation Dependence Through Raman Spectroscopy, Alexandra J. Leandre, Joseph Lussier, Brittany Morgan, Michael Rodriguez
Undergraduate Research Opportunities Program (UROP)
Raman spectra were taken of olivine for analysis of vibrational energy intensity ratios. This allowed for determination of its crystal orientation. Garnet inclusions in peridotite were mapped and Raman spectra were taken for these as well. The inclusions could not identified, and data from the Raman spectra proved inconclusive due to difficulty in removing background signal.
High Pressure Structural Studies On Eus Nano Particles Up To 52 Gpa, Kristie Canaday, Ravhi S. Kumar
High Pressure Structural Studies On Eus Nano Particles Up To 52 Gpa, Kristie Canaday, Ravhi S. Kumar
Undergraduate Research Opportunities Program (UROP)
Crystal size reduction in bulk materials changes the structural and magnetic properties considerably [1]. More importantly the transition pressure is strongly influenced by temperature, pressure, and the crystallite size effect. Rare earth europium chalcogenides crystallize in the NaCl (rock salt) type structure. The interest in Eu nanomaterials is motivated by the possibility of their use in magnetic devices [2,3]. Recent studies suggest that europium chalcogenide nanocrystals exhibit significant changes in their structural and magnetic properties, compared to bulk chalcogenides, when the nanocrystal diameter decreases. The crystal structure and phase transition behavior of EuS nanoparticles have been investigated and compared as …
Magnetic Ordering Phase Transitions Of Gd2sn2o7, Gordon Tam, Andrew Cornelius, Daniel Antonio
Magnetic Ordering Phase Transitions Of Gd2sn2o7, Gordon Tam, Andrew Cornelius, Daniel Antonio
Undergraduate Research Opportunities Program (UROP)
Pyrochlores with magnetic rare earth ions are a topic of interest due to unusual results brought about by their high degree of geometrical frustration. The lattice structure prevents the magnetic spin interactions from finding a single minimum energy state, which leads to a nonzero residual entropy[1]. By analyzing the heat capacity at low temperatures, the type of magnetic interaction can be determined and the temperatures at which long-range magnetic ordering and magnetic field induced splitting of energy states occur.
Modeling The Deformation Of Fayalite, Greg Hoth, Mike Brawner, Pamela Burnley
Modeling The Deformation Of Fayalite, Greg Hoth, Mike Brawner, Pamela Burnley
Undergraduate Research Opportunities Program (UROP)
We are studying how the mineral fayalite deforms under stress while it is subject to high pressures and temperatures. Specifically, we are analyzing x-ray diffraction spectra obtained from experiments with the D-DIA apparatus at Brookhaven national labs. By fitting peaks to the diffraction spectra, we can calculate the spacing between lattice planes of fayalite and so we can observe how this spacing changes over time as the crystal structure deforms We hope to show that this deformation can be modeled using an Elastic Plastic Self Consistent model. In such a model, the material is treated as a cluster of independently …