Дисертації з теми "Diamond Anvil Cell (DAC)"
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Hadjikhani, Ali. "Raman Spectroscopy Study of Graphene Under High Pressure." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/656.
Повний текст джерелаBegen, Burak. "INFLUENCE OF PRESSURE ON FAST DYNAMICS IN POLYMERS." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1195437587.
Повний текст джерелаDzyabura, Vasily. "Pathways to a Metallic Hydrogen." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10737.
Повний текст джерелаPhysics
Sly, Jonathan L. "High-pressure optical studies of III-V semiconductors using the diamond anvil cell." Thesis, University of Surrey, 1995. http://epubs.surrey.ac.uk/843077/.
Повний текст джерелаOkuchi, Takuo, George D. Cody, Ho-kwang Mao, and Russell J. Hemley. "Hydrogen bonding and dynamics of methanol by high-pressure diamond-anvil cell NMR." American Institute of Physics, 2005. http://hdl.handle.net/2237/7067.
Повний текст джерелаSmith, D. "Hydrogenation of monolayer graphene in the diamond anvil cell and supercritical phenomena in methane." Thesis, University of Salford, 2016. http://usir.salford.ac.uk/38156/.
Повний текст джерелаKondrat'yev, Andreiy I. "Finite element modeling and computer simulation of stresses and strains in diamond anvil cell devices." Birmingham, Ala. : University of Alabama at Birmingham, 2006. https://www.mhsl.uab.edu/dt/2008r/kondratyev.pdf.
Повний текст джерелаAdditional advisors: Heng Ban, Renato P. Camata, Krishan K. Chawla, Joseph G. Harrison. Description based on contents viewed Feb. 13, 2009; title from PDF t.p. Includes bibliographical references (p. 124-126).
Nikitin, Sergey. "Laser ultrasonics in a diamond anvil cell for investigation of simple molecular compunds at ultrahigh pressures." Thesis, Le Mans, 2015. http://www.theses.fr/2015LEMA1005/document.
Повний текст джерелаThis PhD research work is devoted to the use of laser ultrasound in high-pressure physics. The research is done using the recently established technique of laser ultrasonic measurements in a diamond anvil cell which allows investigation of the sound propagation and determination of the acoustic wave velocities at ultrahigh pressures. Time domain Brillouin scattering was applied here to depth-profiling of polycrystalline aggregate of ice compressed in a diamond anvil cell to megabar pressures. The technique allowed examination of characteristic dimensions of elastic inhomogeneities and texturing of polycrystalline ice in the direction, normal to the diamond anvil surfaces with sub-micrometer spatial resolution via time-resolved measurements of variations in the propagation velocity of the acoustic pulse travelling in the compressed sample. It was applied to measure the acoustic velocities in H2O ice up to 84 Gpa. The developed imaging technique provides, for each crystallite (or a group of crystallites) in chemically homogeneous transparent aggregate, usable information on its orientation as well as on the value of the elastic modulus along the direction of the sound propagation. This extends the basis for a successful application of highly developed micromechanical models of solids deformation at mbar pressure. On long term, such experiments extended to earth’s minerals and high or low temperatures would insure a significant progress in understanding of convection of the earth’s mantle and thus evolution of this and other planets
Pigott, Jeffrey Scott. "Exploration of Earth's Deep Interior by Merging Nanotechnology, Diamond-Anvil Cell Experiments, and Computational Crystal Chemistry." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1435154850.
Повний текст джерелаLord, Oliver T. "Experimental Constraints on the Chemistry of the Earth's Core : Novel approaches using the Laser-Heated Diamond Anvil Cell." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520173.
Повний текст джерелаAprilis, Georgios [Verfasser], and Natalia [Akademischer Betreuer] Dubrovinskaia. "Pulsed laser heating in the diamond anvil cell : applications in geo- and material sciences / Georgios Aprilis ; Betreuer: Natalia Dubrovinskaia." Bayreuth : Universität Bayreuth, 2021. http://d-nb.info/1227444648/34.
Повний текст джерелаLeong, Daniel Nichol. "The technology of electrical feedthroughs into the diamond anvil cell and its applications to high pressure electro-optical spectroscopy." Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/844190/.
Повний текст джерелаCastro, Rosane de Paula. "Avaliação da dependência com a pressão de propriedades estruturais de compostos orgânicos de interesse farmacêutico." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8563.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This thesis presents the structure determination using single crystal x-ray crystallography of four drug candidates under ambient conditions of temperature and pressure, as well as submitted to high pressure. The crystallographic analysis of this type of compound allows to obtain the three-dimensional structure in an unambiguous way. This information is useful for the development process of new drugs in order to achieve the planned properties, such as the study of combinations of the drug with the excipients to be used to guarantee the rate of expected release of the drug in the human body and the optimization of interaction between the drug and the target. Furthermore during the process of drug manufacturing in the pharmaceutical industry polymorphic phases may arise due to the application of pressure, which occurs during grinding and in the preparation of tablets, which may alter the bioavailability, solubility and stability of the medicament. Thus, identifying the conditions under which such modifications may occur guarantees the reliability of the final product. In this sense, the crystallization and crystallographic analysis of drug candidates developed by the Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio) of the Universidade Federal do Rio de Janeiro (UFRJ) was carried out. The compounds analyzed were: LASSBio-1773 and LASSBio-1774, which have hypoglycemic activity, LASSBio-1606, with anti-inflammatory properties, and LASSBio-1735, which has been shown to be active against several types of cancer. For the compounds LASSBio-1774 and LASSBio-1606 X-ray diffraction at high pressures was also performed with Diamond Anvil Cell (DAC), determining their unit cells and analyzing the effects of pressure on the crystalline arrangement. In both compounds reversible phase transitions were observed. The analysis of the structural changes for LASSBio-1774 due to pressure was performed with the aid of strain tensors.
Nesta tese serão apresentados os resultados de determinação estrutural por difração de raios X de monocristais de candidatos a fármacos em condições ambientes de temperatura e pressão, assim como submetidos à altas pressões. A análise cristalográfica desse tipo de composto permite obter a estrutura tridimensional de maneira inequívoca. Essa informação é útil para o processo de desenvolvimento de novos fármacos a fim de se alcançar as propriedades planejadas, tais como o estudo de combinações do fármaco com os excipientes a serem utilizados para garantir a taxa de liberação esperada do fármaco no corpo humano e a otimização da interação entre o fármaco e o alvo. Além disso, durante o processo de produção na indústria farmacêutica, podem surgir fases polimórficas devido à aplicação de pressão, que ocorre durante a moagem e na preparação de comprimidos, podendo alterar a biodisponibilidade, solubilidade e estabilidade do medicamento. Assim, identificar as condições nas quais tais modificações podem ocorrer, garante a confiabilidade do produto final. Nesse sentido, no presente trabalho foram realizadas a cristalização e análise cristalográfica de candidatos à fármacos desenvolvidos pelo Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio) da Universidade Federal do Rio de Janeiro (UFRJ). Os compostos analisados foram: LASSBio-1773 e LASSBio-1774, que possuem atividade hipoglicemiante, LASSBio-1606, com propriedade anti-inflamatória, e LASSBio-1735, que se mostrou ativo contra diversos tipos de câncer. Para os compostos LASSBio-1774 e LASSBio-1606 foi realizada também a difração de raios X em altas pressões, com a Diamond Anvil Cell (DAC), determinando suas células unitárias e analisando os efeitos da pressão sobre o arranjo cristalino. Em ambos os compostos foram observadas transições de fase reversíveis. Para o LASSBio-1774 a análise das mudanças estruturais devidas à pressão foi realizada com o auxílio dos tensores de strain.
Karandikar, Amol [Verfasser], Björn [Gutachter] Winkler, and Lars [Gutachter] Ehm. "Development of the flash-heating method for measuring melting temperatures in the diamond anvil cell / Amol Karandikar ; Gutachter: Björn Winkler, Lars Ehm." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2016. http://d-nb.info/1116426528/34.
Повний текст джерелаNajiba, Shah. "High Pressure and Low Temperature Study of Ammonia Borane and Lithium Amidoborane." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1388.
Повний текст джерелаPigott, Jeff S. "The Viscosity of Water at High Pressures and High Temperatures: A Random Walk through a Subduction Zone." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299607953.
Повний текст джерелаSundberg, Sara Nanna Kristina. "Optical and Raman Spectroscopic Studies on H2O at High Pressure." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5934.
Повний текст джерелаIn this thesis, volumetric, optical and vibrational properties of H2O were studied at high pressures by combining techniques of Raman spectroscopy, interferometry and optical imaging. Pressures up to 7 GPa were generated in the diamond anvil cell (DAC), entering the stability fields of liquid water and ices VI, VII and VIII.
A new integrated system for Raman, interferometric and optical-imaging studies has been built up. Utilizing the interferometric patterns formed between closely-spaced diamond anvils, the system allowed the complete monitoring and control of pVT-conditions of studied ices, as well as the determination of their dispersive properties in the visible range using the Airy equation and Cauchy formulation. This setup and technique thus represent a novel tool for the precise determination of equations of state (EOSs) of transparent materials, including fluids and low-Z materials.
Data-sets on thermal pressure were obtained from heating/cooling experiments carried out on the liquid water and used for checking the mutual consistency between published EOSs. A pVT-EOS for ice VIII and room temperature isotherms for ices VI and VII at 300 K were derived by combined methods of interferometry and imaging. While the agreement with the available EOSs of ices VII and VIII is very good, some inconsistent EOSs of ice VI were identified in the present study.
The technique of micro-Raman spectroscopy was applied for the monitoring of phase transformations, identification of various ice phases and for studying the response of vibrational symmetry modes to varying conditions. Analysis based on the combination of the pT-dependencies of the vibrational frequencies with the pVT-EOSs showed that, in the studied ices, the implicit volume-driven contributions dominate over the explicit phonon effects in the total temperature-induced changes in vibrational frequencies. The results provide valuable insight on the anharmonic effects and interactions in these molecular solids.
Sundberg, Sara Nanna Kristina. "Optical and Raman Spectroscopic Studies on H2O at High Pressure." Doctoral thesis, Uppsala universitet, Institutionen för geovetenskaper, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5934.
Повний текст джерелаBoye, Shawn Alexander. "Magnetotransport Measurements of Ni Thin Films." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4653.
Повний текст джерелаThis thesis presents transverse magnetoresistance (MR) and Hall resistivity measurements of nickel thin films at temperatures between 280 and 455 K and pressures up to 6 GPa. An experimental system was developed for conducting precise magnetotransport measurements using the current reversal and van der Pauw techniques in combination with a 10 T superconducting magnet. Polycrystalline Ni0.985O0.015 thin film samples were manufactured with preexisting point contacts allowing highly reproducible magnetotransport measurements at pressure in the diamond anvil cell (DAC).
The magnetic resistivity above the technical saturation of the magnetization was found to decrease linearly to the highest applied fields, 10 T, while the field derivative, 0.010-0.018 µΩ cm T-1 between 280 and 316 K, increased with temperature and decreased with pressure. The decrease in the magnetoresistance is attributed to spin wave damping of electron-magnon scattering processes at high fields. The magnon mass, 535(14) meV Å2 at 0 K and 0 GPa, determined from longitudinal magnetic resistivity theory is a slightly increasing function of pressure. Correlation between the zero field resistivity and the extraordinary Hall coefficient (EHC) confirmed side jump scattering as the dominant diffusion mechanism at 0 GPa, however, skew scattering was found to become increasingly important with pressure.
The effect of oxygen and pressure on the density of states (DOS) at the Fermi level was investigated through total energy band structure calculations using a periodic supercell of 64 atoms to simulate the sample chemistry. The DOS of Ni0.985O0.015 at the Fermi level was found to increase by 27% at 10 GPa relative to 0 GPa. However, when compared to the results for pure Ni, decreases of 60% and 23% occurred for the corresponding calculations at 0 and 10 GPa. The relative differences in the magnetic resistivity are attributed to competing effects between the DOS, average magnetic moment and magnon mass.
The technique developed for conducting magnetotransport measurements at pressure is applicable to the study of electronic diffusion in ferromagnets as well as geophysical problems such as the geodynamo.
Konôpková, Zuzana. "Thermal Conductivity of Materials under Conditions of Planetary Interiors." Doctoral thesis, Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-150396.
Повний текст джерелаColeman, Amy Louise. "Studies of dynamically and statically compressed antimony." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31334.
Повний текст джерелаToraille, Loïc. "Utilisation de centres NV comme capteurs de champs magnétiques à haute pression dans des cellules à enclumes de diamant." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN056/document.
Повний текст джерелаPressure is a physical variable that alters structural, electronic and magnetic interactions in all materials. Reaching high pressure is thus a way to create new materials such as superconductors with record critical temperatures. High pressures can be enabled through the use of diamond anvil cells (DAC), which can attain pressures of several hundred of GPa. It is however quite a challenge to measure magnetic properties of materials inside a DAC because of the very small sample volume available and of technical constraints. In this PhD thesis, we demonstrate the use of a magnetometry method based on the electronic spin resonance of NV centers in diamond. These NV centers are fabricated directly on top of one of the DAC anvils, which places them in contact with the magnetic sample.In the first chapter, we describe how the DAC works and we present the different ways of probing magnetic properties that have been developed for high pressure conditions. We then explain the operating principle of NV magnetometry and use this method to measure the magnetization of a micro-magnet at ambient pressure. The sensitivity of this measure is comparable to that of SQUID magnetometry. In the third chapter, we discuss how mechanical constraints modify the spin resonance of the NV center, and describe how this effect combines with the influence of an external magnetic field. By decoupling these two effects, we can observe the magnetic phase transition of iron around 15 to 30 GPa, which is displayed in the fourth chapter. Finally, the last chapter briefly presents the context and stakes associated with the synthesis of superconducting superhydrides with high critical temperature. We perform an optical detection of a superconducting phase inside a DAC with NV centers through the observation of the Meissner effect in MgB2 at a pressure of 7 GPa and with a critical temperature of 30 K
Marizy, Adrien. "Super-hydrures sous pression pour le stockage de l’hydrogène et la supraconductivité : développement d’outils et résultats sur H3S, CrHx, LiBH4 et NaBHx." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX115/document.
Повний текст джерелаRecently, under pressures of several gigapascals, new hydrides have been synthesised with striking properties that may herald technological breakthroughs for hydrogen storage and superconductivity. In this PhD thesis, several superhydrides have been studied experimentally and simulated by DFT. The pressure phase diagrams of LiBH4 and NaBH4, two compounds of interest for hydrogen storage, have been explored thanks to X-ray diffraction and Raman and infrared spectroscopy up to pressures of 300 GPa without observing any decomposition. The insertion of hydrogen inside NaBH4 generates the superhydride NaBH4(H2)0.5. To refine the interpretation of the record superconductivity found in H2S under pressure at 200 K, the superhydride H3S has been synthesised from S and H elements. The results of the diffraction study seem to be at odds with the commonly accepted interpretation that Im-3m H3S is responsible for the superconductivity observed and leaves the door open to other interpretations. Finally, CrHx hydrides with x = 1, 1.5 and 2 have also been synthesised from the elements and characterised by X-ray diffraction. Although these hydrides do correspond to the ones that had been numerically predicted, the absence of the expected higher stoichiometries is discussed. To measure the superconductivity temperatures calculated for MHx hydrides, a miniature diamond anvil cell which allows the detection of a Meissner effect has been developed
Hrubiak, Rostislav. "Exploring Thermal and Mechanical Properties of Selected Transition Elements under Extreme Conditions: Experiments at High Pressures and High Temperatures." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/696.
Повний текст джерелаSchmidt, Christian. "Experimental Study of the PVTX Properties in Part of the Ternary System H₂O-NaCl-CO₂." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30610.
Повний текст джерелаPh. D.
Meißner, Thomas. "Exploring Nuclear Magnetic Resonance at the Highest Pressures." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-115023.
Повний текст джерелаGauvin, Mélanie. "Approche analytique in situ du mécanisme anti-usure des phosphates de zinc." Ecully, Ecole centrale de Lyon, 2008. http://www.theses.fr/2008ECDL0021.
Повний текст джерелаEco-friendly lubricant additives are of primary environmental and economical importance. Their design rely on our understanding of anti-wear additives such as the zinc dialkyldithiophosphate (ZDDP). ZDDP has the remarkable property of forming a thin protective coating against wear, called ZDDP-tribofilm ,at the interface of a boundary lubricated contact. However, detailed reactional pathwaγs leading to the ZDDP tribofilm formation and mechanisms responsible for wear inhibition are still unsolved. High local pressures in the range of several giga pascals in a boundary lubricated contact are likely to modify the atomic structure and macroscopic properties of materials at this interface. Our work focuses on an in situ analysis of structural modifications of ZDDP-like model compounds when exposed to high hydrostatic pressures, up to 20 GPa. We chose to model the ZDDP additive by zinc phosphate compounds (ZP) after performing tribological tests under boundary lubrication conditions using colloidal Zn3 (P04)2, ,Zn2P207 and Zn(P03 )2 compounds mixed to a poly-alpha-olefin oil, at ambient temperature formation of a tribofilm is observed at the interface for Zn3(P04)2 while it is negligible for Zn2P207 and Zn(PO3)2 materials. Mechanical and topographical properties of the amorphous film formed from Zn3(P04)z at the interface, show some similarities with ZDDP tribofilm. In situ micro-Raman spectroscopy was used to probe P04 tetrahedra structural modifications in ZP compounds of different phosphate chain lengths, up to 20 GPa. Pressure had no effect on PO4 tetrahedra polymerization in tested materials and cannot account for the formation of long-chain phosphates found in the ZDDP-tribofilm. Between 0. 1 MPa. And 4 GPa, α -Zn3(P04 )2 Raman spectra undergo important modifications which were attributed to a phase transition of the initial crystalline structure. Above 4 GPa,Zn3(P04 )2 Raman spectra show a progressive loss of the long-rang order in the sample. The structure recovered after decompression is similar to an amorphous Zn3(P04 )2 compound. Local environment of Zn atoms in α Zn3(PO4)2 was investigated under' high static pressure by in situ Zn-K edge EXAFS and XANES spectroscopies. Crystalline order around Zn atoms was found to vanish down to the second sphere of coordination and the mean Zn-O bond length is increased by 0. 046 +0. 005. A when pressure increases from 0. 1 MPa to 3. 5 GPa. The coordination number around Zn atoms does not change significantly at a maximal pressure of 7 GPa. The disordered local structure of zinc atoms observed at high pressure is conserve a decompression. Finally, a reciprocating tribometer combined with in situ micro-Raman spectroscopy was used to probe α-Zn3(P04)2 structural transformations occurring under combined shear and pressure constrains at ambient temperature. Tribolocically constrained Zn3(P04)2 structures were found to be identical to high pressure phases formed in static high pressure experiment and led to the formation of an amourphous zinc orthophosphate tribofilm
Dilner, David. "Behavior of cutting tool coating material Ti1-xAlxN at high pressure and high temperature." Thesis, Linköping University, Department of Physics, Chemistry and Biology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-52773.
Повний текст джерелаThe high pressure and high temperature (HPHT) behavior of Ti1-xAlxN coatings on cutting tool inserts have been of interest for this diploma work. A literature study of HPHT techniques as well as measurement methods has been done. A diamond anvil cell (DAC) would be a good device to achieve high pressure and high temperature conditions on small samples. Another way to obtain these conditions would be a cutting test, which has been performed on a Ti1-xAlxN coated cutting tool insert with x = 0.67. Also a cubic press could be used to apply HPHT on a Ti1-xAlxN sample or a large volume press on a whole cutting tool insert. To measure hardness on thin coatings a nanoindentor could be used, which have been done on heat-treated Ti0.33Al0.67N and TiN samples. X-ray diffraction (XRD) is a suitable method to measure phase composition of a sample and was performed on the cutting tested insert as well as on an untreated reference insert. Three ways to continue this project have been outlined all starting with more comprehensive cutting tests.
Dilner, David. "Behavior of cutting tool coating material Ti1-xAlxN at high pressure and high temperature." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-52773.
Повний текст джерелаKolesnikov, Anton. "Experimental investigation of hydrocarbon formation and transformation under Earth´s upper mantle conditions." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-27017.
Повний текст джерелаQC 20101203
Biggs, Timothy James. "Studies of crystalline organic molecular materials under extreme conditions." Thesis, University of Oxford, 2006. http://ora.ox.ac.uk/objects/uuid:51dae806-2954-4ea7-a3cb-1980ecb53e98.
Повний текст джерелаSonneville, Camille. "Étude des propriétés élastiques des verres d’oxydes sous haute pression : implications structurales." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10114/document.
Повний текст джерелаThe structural study of glasses under pressure is of fundamental interest in Physics, Earth Science and is technologically important for the comprehension of industrial material properties. The elastic anomaly at 2.5GPa in pure silica glass is a well known phenomenon and its existence is more than likely in GeO2 glass. In this work the persistence of the elastic anomaly in more complex and more widely glass compositions as sodium alumino silicate glasses was studied. The elastic anomaly was studied in situ in GeO2 and three sodium alumino silicate glasses by Brillouin and Raman scattering. The studied sodium alumino silicate glasses had the following compositions : (Al2O3)X(Na2O)25−X(SiO2)75 where X=0, 6 et 12% and is the molar percentage of Al2O3. The elastic anomaly was shown to persist in a broad domain of chemical compositions thus its existence is not reduced to pure silica glass. Its existence seems to be linked to the presence of 6 membered rings. Beyond the elastic limit, the structural modifications was studied in pure silica, GeO2 glass and sodium alumino silica glasses (with X=0, 2, 6, 9, 12 et 16% of Al2O3) in order to structurally better understand the densification phenomenon. Firstly the elastic anomaly was studied by Brillouin scattering experiments, was shown to progressively disappear with the densification. This progressive disappearance was interpreted in terms of a progressive structure induced transformation from a Low Density Amorphous form (LDA) into a High Density Amorphous form (HDA) : LDA → HDA. In situ and ex situ studies by Brillouin and Raman scattering, Nuclear Magnetic Resonance (NMR) and X-ray Absorption Near Edge Structure (XANES) showed that the pressure induced structural transformation was highly dependent of the glass chemical composition. For instance the presence of sodium cations promotes short range order modifications, such as formation of highly coordinated species (Al, Si) and network depolymerization. On the other hand, glasses with a high aluminum concentration show a densification process closer to that of pure silica glass, with mainly middle range order structural modifications such as a decrease of the inter-tetrahedral angle or ring size decrease
Medeghini, Fabio. "Optics and acoustics with a single nano-object : environment effects." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1026/document.
Повний текст джерелаIn this thesis, the properties of a single nanoparticle have been tuned altering its environment. Specifically, in the first part of this work, the surface plasmon resonance of individual gold nanobipyramids has been experimentally studied under a pressure adjustable surrounding and its evolution physically framed thorough theoretical modeling.In order to access to the single nanoparticle optics while generating a hydrostatic high-pressure environment, a challenging combination of the spatial modulation spectroscopy technique with the diamond anvil cell method has been achieved.In the second part of the thesis, the acoustic vibrations of individual gold nanodisks on sapphire substrate has been experimentally characterized via pump&probe spectroscopy. Particular attention has been paid to their damping as a function of the disks aspect-ratio enlightening the presence of quality-factors enhancements.Numeric modeling has provided a physical insight for the observed amplifications, showing that modes hybridizations occur at specific aspect-ratios, potentially reducing the acoustic energy loss towards the interface disk/substrate
Berkani, Sophia. "Comportement tribologique et analyses in-situ de polyphosphates de zinc : apport de la spectroscopie Raman." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00963748.
Повний текст джерелаMontagnac, Gilles. "Spectroscopie Raman résonnante UV in situ à haute température ou à haute pression." Thesis, Lyon, École normale supérieure, 2012. http://www.theses.fr/2012ENSL0784/document.
Повний текст джерелаI applied UV resonant Raman spectroscopy (UVRRS) to an ‘in situ’ study of carbon materials at very hight temperature (> 2000 K) or at high pressure (< 1 GPa).The advantages of UVRRS are presented in the first part of this PHD thesis, and used to investigate details of the composition and structure of disordered carbon materials such as: (1) n-type nanocrystalline films, (2) carbonaceous matter in chondrites and (3) tholins, HCN synthetic samples of Titan 's atmosphere.‘In situ’ Raman studies are limited to 2000 K by the visible black-body emission. I designed a high temperature cell to perform UVRRS above this limit. The second part of the manuscript presents Raman spectra of pyrolitic graphite and HOPG up to 2700 K. This data are consistent with anharmonic models up to 900 K, and show the coupling effects of electron-phonon and phonon-phonon. The last one dominates the anharmonicity above 1000 K. The Raman spectra was calibrated as a function of temperature and became a “thermometer” up to 2700 K.For high pressure measurements in the third part, I modified an anvil cell to study by UVRRS, the vibrational changes induced by pressure on very luminescent molecular organic crystals. I present an analysis at 244 nm of resonant Raman modes of perylene crystal under hydrostatic pressure up to 0.8 GPa. Some of them have a non linear feature under pressure, revealing structural and planar modifications of the molecules
Pal, Srishti. "Spectroscopic and Diffraction Signatures of Quantum Spin Liquids, Skyrmion Lattices and Transition Metal Dichalcogenides at Low Temperatures and High Pressures." Thesis, 2022. https://etd.iisc.ac.in/handle/2005/5727.
Повний текст джерелаJy, Kaohsiung, and 支高雄. "The compressibility of NiO in a diamond anvil cell." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/38897573471432961227.
Повний текст джерела楊聖恩. "Raman Spectroscopic Study of CacO3 in Diamond Anvil Cell." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/67034766020003382324.
Повний текст джерела國立臺灣大學
地質學研究所
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The high-pressure Raman spectroscopic experiments of calcite were carried out in a diamond anvil cell with methanol-enthanol medium up to 25 GPa at room temperature. We have observed only two relative intense Raman peaks of v4 and v1 in calcite up to 7 GPa and 25 GPa, respectively. The vibrational frequencies of calcite were found to increase linearly under pressure with their slopes, dv/dP, range from 1.73 to 6.81cm-1/GPa. The appearance of new Raman peaks and the change in slope of these observed modes may indicate that calcite undergoes a series of phase transitions, i.e. CaCO3-Ⅰ→CaCO3-Ⅱ and CaCO3-Ⅱ→CaCO3-Ⅲ ; moreover, these changes might also related to the distorted trigonal planar CO3 groups during compression. A new high-pressure phase was found to coexist with CaCO3-Ⅲ above 14 GPa and the complete transformation to the new phase took place at about 18 GPa. We interpret this new high-pressure phase as calcite-Ⅵ. In addition, all of the phase transitions of calcite observed in our experiment are reversible. On the basis of the present Raman spectroscopic observation, no sign of phase transition in aragonite was found up to 22 GPa. In comparison with the Raman data of calcite, it seems that aragonite and calcite-Ⅵ with a simiar Raman vibrational mode above 18 GPa. The vibrational frequency of v1 increases with decreasing C-O interatomic distance during compression in the CaCO3 phases, We also interpret the cause of the frequencies of v1 and v4 decrease with increasing the ionic radii of cations for some carbonate minerals with calcite and aragonite structure. Finally, according to the unit-cell parameters and the relationship of the pressure-induced C-O bond shortening, we inferred the CO3 groups are more compressible than CaO6 octahedra in pressure range from the ambient pressure to 1.8 GPa. However, above 1.8 GPa, CaO6 octahedra become more compressible than CO3 groups. In comparison with previous studies, we found the compressibilities of C-O bonds in CaCO3-III and CaCO3-VI are similar with those of aragonite, dolomite and magnesite above 2 GPa. However, the C-O bonds in calcite are more compressible than the other carbonate minerals below 2 GPa.
Lin, Jung-Fu, and 林俊孚. "Raman Spectroscopic Studies of Hydrous Minerals in Diamond Anvil Cell." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/19424954032441245526.
Повний текст джерелаWright, Andrew Osbourn. "Solid state defect dynamics measured with site selective spectroscopy employing a diamond anvil cell." 1994. http://catalog.hathitrust.org/api/volumes/oclc/31514073.html.
Повний текст джерелаMulcahy, Cara Kim. "Hydrothermal diamond anvil cell studies a possible new calibration mineral and applications to the hydrouscarbonate mineral, nesquehonite /." 2006. http://etd.utk.edu/2006/MulcahyCara.pdf.
Повний текст джерелаGroß, Juliane [Verfasser]. "Mineral solubility measurements at high pressures: Redesigning the hydrothermal diamond anvil cell, crystal volume computations and birefringence mapping / von Juliane Groß." 2009. http://d-nb.info/997264314/34.
Повний текст джерелаPatterson, Donald Eugene. "Studies involving novel inorganic materials: I. The direct fluorination of diamond, high-temperature superconductors, and selected organic materials. II. The use of gem-cut cubic zirconia in the diamond anvil cell." Thesis, 1989. http://hdl.handle.net/1911/16279.
Повний текст джерелаGawraczyński, Jakub. "Optical spectroscopy of selected divalent silver compounds." Doctoral thesis, 2019. https://depotuw.ceon.pl/handle/item/3382.
Повний текст джерелаThis doctoral dissertation describes research on silver compounds carried out with a range of spectroscopic methods. The main focus of the thesis was on divalent silver compounds: AgF2, AgSO4, AgSO4∙H2O, (AgF)BF4, CsAgF3, RbAgF3, and high-temperature form of KAgF3. In addition, other silver compounds were investigated, particularly AgF and silver(I, III) oxide AgO. All compounds were studied by FT-FIR spectroscopy, some were also investigated with Raman spectroscopy (at ambient or high pressure), MIR, NIR, as well as UV and visible absorption spectroscopy and by inelastic neutron scattering. The main scope of the work was to get insight into vibrational structure of the studied compounds as well as understand their pressure-induced phase transitions. The second goal was to determine magnetic superexchange constants for 2D AgF2 from Raman scattering spectra, and for 1D AgFBF4 from NIR-absorption spectra. The auxiliary task, dictated by the course of the experimental work, was to understand photochemical decomposition of AgF2 and AgSO4. The spectroscopic measurements of AgIISO4 prepared using the new electrosynthesis method in concentrated H2SO4 showed its similarity with the product of chemical synthesis developed earlier, albeit substantial differences in reactivity to water vapor were also found. In addition, the laser-induced decomposition of AgIISO4 was observed and it was shown that the decomposition product is dependent on the wavelength of the laser used. A similar photosensitivity was observed in AgIISO4∙H2O. The hydrate was also studied spectroscopically from far-infrared to UV, which allowed determination of the orbital splitting parameters as well as has provided the supplementary evidence for the presence of water molecules in its crystal structure. Research on AgF at high pressure showed the presence of several Raman bands in contrast with predictions of group theory (no Raman-active bands), some of them probably originating from color centers or overtone of the IR-active fundamental. Research on AgF2 proved its high photosensitivity to laser light. Laser-induced photodecomposition product has been studied in the range from atmospheric pressure up to 47 GPa. The decomposition product seems to contain Ag(II)F42– anion, notably Ag(I)2Ag(II)F4, which is the first mixed-valence Ag(I)/Ag(II) fluoride known. Pressure dependence of the characteristic Raman band for this phase was measured up to 47 GPa. In addition, using Raman scattering spectroscopy and inelastic neutron scattering, I have successfully identified and measured for the first time the bimagnon transitions in 2D antiferromagnet, AgF2, and determined the value of the intra-sheet magnetic superexchange constant, J. The large value of J=70 meV sets this compound second only to lamellar oxocuprates(II). (AgF)BF4 has been characterized by Raman scattering, inelastic neutron scattering, IR absorption and reflection spectroscopy. The characteristic band appearing in the NIR absorption spectra enabled estimation of the intra-chain magnetic superexchange constant for this compound to be about 270 meV. This value surpasses the largest known superexchange constant ever measured (240 meV for Sr2CuO3). Research on AgO conducted under a high pressure showed no pressure-induced decomposition or comproportionation of this compound to no less than 74 GPa. Due to the good agreement of the experimental Raman band positions with those derived from the theoretical calculations made on the AgO high-pressure models, it was possible to demonstrate the existence of two structural phase transitions in the pressure range from 0 to 74 GPa. The research carried out on three alkali metal fluoroargentates: CsAgF3, RbAgF3, and high-temperature form of KAgF3 has shown that despite clear structural differences between them, the Fourier transmission spectra in the far infrared range of all compounds show substantial similarity.
Lu, Chang. "Elasticity of single-crystal iron-bearing pyrope to 20 GPa and 750 K." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5456.
Повний текст джерелаtext
Schauries, Daniel. "Ion Tracks in Apatite and Quartz and Their Behaviour with Temperature and Pressure." Phd thesis, 2016. http://hdl.handle.net/1885/112508.
Повний текст джерелаSaouane, Sofiane. "Extending the Search Space for Novel Physical Forms of Pharmaceuticals and Biomolecules using High-Pressure Techniques." Doctoral thesis, 2015. http://hdl.handle.net/11858/00-1735-0000-0028-878A-D.
Повний текст джерелаMeißner, Thomas. "Exploring Nuclear Magnetic Resonance at the Highest Pressures: Closing the Pseudogap under Pressure in a High Temperature Superconductor." Doctoral thesis, 2012. https://ul.qucosa.de/id/qucosa%3A11967.
Повний текст джерелаRUELLO, GIOVANNA. "Pressure dependence of the intermediate-range structure and the boson peak in oxide glasses." Doctoral thesis, 2018. http://hdl.handle.net/11570/3120290.
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