Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 39 for “"diamond anvil cell"”.
-
Hydrogenation of monolayer graphene in the diamond anvil cell and supercritical phenomena in methane
… under high pressure (2.6 – 6.5 GPa) in a diamond anvil cell. The hydrogen content of functionalised samples can be estimated by observing the Raman spectrum and such analysis suggests that the diamond anvil cell method currently hydrogenates samples to an extent that is competitive with …
-
Brillouin studies of diopside and H2O
… properties of diopside at high pressure using a diamond anvil cell. The single-crystal elastic constants of diopside have been measured up to 14 GPa using Brillouin spectroscopy, from which the aggregate compressional and shear velocities, adiabatic bulk modulus, shear modulus and their pressure …
-
Nature and Dynamics of Earth and Planetary Cores From High-Pressure Properties of Iron -Rich Alloys
… (TDTR) method combining with the diamond anvil cell technique (Chapter 5). I report high-pressure thermal conductivity data of water and ice phases up to 11 GPa and at 300 K. The thermal conductivity of Ice VII increases by more than a factor of ∼4 from 3.3 to 11 GPa. The data …
-
The c33 elastic constant of MoS2 as a function of pressure and the deposition of multilayer thin films by sputtering
… MoS2 flakes was measured up to 11 GPa using a diamond anvil cell and picosecond interferometry. The resulting elastic constants were similar those predicted by hybrid density functional theory calculations by Peelaers and Van de Walle, but lower than those calculated from lattice constant …
-
In situ Raman spectroscopy of pressure-induced phase transformations in DyPO₄ and GdxDy(1-x)PO₄
… temperature under high pressures inside a diamond anvil cell with in situ Raman spectroscopy. The Raman active modes of the xenotime structure were observed at low pressures and the appearance of new Raman peaks at higher pressures indicate a phase transformation to a lower symmetry …
-
New technologies for spectroscopy of materials under static and shock compression
… Raman scattering spectroscopy with diamond anvil cell technology. The samples used were benzenethiol (BT) and benzene methane thiol (BMT) adsorbed onto photonic substrates composed of silver films over polystyrene nanospheres. Results indicated that the thiols were mobile, not fixed, …
-
Investigation of "conventional" superconductivity in ternary cerium compounds through high pressure studies
… (up to 20 kbar) and a specially designed diamond anvil cell for higher pressures (up to 66 kbar). Trends are presented for the variation of the superconducting transition temperatures with changes in external pressure;Results are also included from measurements of static magnetic …
-
High pressure surface enhanced Raman scattering spectroscopy
… spectroscopy (SERS) was combined with the diamond anvil cell technique to study molecular monolayers and single molecules under high pressure. Vibrational spectra up to 8 GPa were obtained for self-assembled monolayers (SAMs) of the energetic material simulant 4-nitrobenzenethiol (NBT). A …
-
Elasticity of single-crystal iron-bearing pyrope to 20 GPa and 750 K
… up to 20 GPa and 750 K in an externally-heated diamond anvil cell. The derived aggregate adiabatic bulk and shear modulus (KS0, G0) at ambient conditions are 168.2 (±1.8) GPa and 92.1 (±1.1) GPa, respectively, consistent with literature results. Using the third-order Eulerian finite-strain …
-
Barocaloric effects in barium-dicalcium propionate salts
… x-ray diffraction measurements in a diamond anvil cell with synchrotron radiation, I confirmed reversible pressure-driven phase transitions at room temperature for the propionate salt and at ~373 K in the butyrate salt. Together, my findings suggest that barium dicalcium propionate …
-
Raman Spectroscopy and Synchrotron X-ray Diffraction Study of Lunar and Terrestrial Plagioclase Feldspar at High-Pressure and High-Temperature Conditions
… were also conducted using laser heating diamond anvil cell and synchrotron X-ray diffraction. Results reveal pressure/temperature-induced amorphization and crystallization kinetics of high-pressure phase changes. The phase diagram of intermediate plagioclase was constructed up to 64 GPa …
-
High Pressure Studies of Superconductivity
… measurements performed in both He-gas and diamond anvil cell systems on various superconductors and on materials in which pressure-induced superconductivity has been predicted. Under pressure the alkali metals undergo a radical departure from the nearly-free electron model. In Li this leads …
-
The origin and behaviour of carbonate minerals in diverse environments: from subduction zones to asteroids
… and X-ray absorption spectroscopy in the diamond anvil cell (DAC). The aqueous solubility of dolomite [CaMg(CO3)2] and magnesite (MgCO3) was investigated using optical solubility experiments in the DAC. Following the experimental chapters, the role of clays in the formation of an iron …
-
Elasticity and phase transitions of stishovite and NaCl at high pressure
… and at high pressures and temperatures in the diamond anvil cell. Experiments were performed in Merrill-Bassett and piston-cylinder types of diamond anvil cells with Ne, KBr, NaCl, Ar, N2, silicone oil, and a ethanol-methanol-water mixture as pressure transmitting media up to 78 GPa at 300K.
-
Experimental Study of the PVTX Properties in Part of the Ternary System H₂O-NaCl-CO₂
… conventional microthermometry, a hydrothermal diamond-anvil cell and Raman spectroscopy. At constant salinity, the high-pressure portion of the solvus migrates to higher pressures and temperatures with increasing carbon dioxide concentration. Immiscibility is possible in this ternary system …
-
Polymeric nitrogen by plasma enhanced chemical vapor deposition
… nitrogen (cg-PN) phase, produced only in a diamond anvil cell at high pressure high temperature conditions and not recoverable under ambient conditions, is shown by the powder diffraction data to be one of the polymeric nitrogen phases synthesized by the plasma process. Density Functional …
-
Developing Levitation Laser-Fused Glasses as Proxies for Lower Mantle Experiments: a Methodological Approach
… characterized, these glasses can be used in diamond anvil cell experiments, where they can act as proxies for an otherwise inaccessible area of the Earth. In addition to the development of this methodology, two web applications produced during this research aid in visualization of both data …
-
Testing theories for thermal transport using high pressure
… thermoreflectance (TDTR), combined with gem anvil cell techniques. I demonstrated that pressure tuning of physical properties of materials is an elegant approach to test the validity of theories for thermal transport. Pressure dependence of the cross-plane thermal conductivity Λ(P) of a …
-
Synthesis, characterization and application of metal-organic frameworks
… GPa, using a synchrotron radiation source and a diamond anvil cell. Both as-synthesized and desolvated samples of IRMOF-1 retained some crystallinity to 6.57 GPa (65 700 atm) and 4.32 GPa (43 2 00 atm), respectively. Both begin to convert to a new material even at pressures as low as 0.21 GPa; …
-
Using high pressure to study thermal transport and phonon scattering mechanisms
… crystals. My primary experimental tools are the diamond anvil cell (DAC) coupled with time-domain thermoreflectance (TDTR). TDTR is a precise optical method well-suited to measuring thermal conductivities and conductances at the nanoscale and across interfaces. The DAC-TDTR method yields thermal …
Page 1 of 2