Olga Narygina

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Mantle convection and plate tectonics are driven by the heat flow from Earth's core to the surface. The radiative contribution to heat transport is usually assumed to be negligible. Here, we report the near-infrared and optical absorption spectra of silicate perovskite, the main constituent of the lower mantle, to 125 gigapascals. Silicate perovskite(More)
Cosmochemical, geochemical, and geophysical studies provide evidence that Earth's core contains iron with substantial (5 to 15%) amounts of nickel. The iron-nickel alloy Fe(0.9)Ni(0.1) has been studied in situ by means of angle-dispersive x-ray diffraction in internally heated diamond anvil cells (DACs), and its resistance has been measured as a function of(More)
We discover that hcp phases of Fe and Fe(0.9)Ni(0.1) undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests itself through anomalous behavior of the Debye sound velocity, c/a lattice parameter ratio, and Mössbauer center shift observed in our experiments. First-principles simulations(More)
The diamond anvil cell (DAC) technique coupled with laser heating has become the most successful method for studying materials in the multimegabar pressure range at high temperatures. However, so far all DAC laser-heating systems have been stationary: they are linked either to certain equipment or to a beamline. Here, a portable laser-heating system for(More)
The stability of perovskite-structured materials at high pressure and temperature is of fundamental interest in solid-state physics, chemistry, and the geosciences. As an alternative to decomposition into oxides or transformation of the CaIrO_{3} postperovskite structure, we observe in situ the breakdown of FeTiO_{3} perovskite into a(More)
Energy-dispersive X-ray absorption spectroscopy is now a well established method that has been applied to a broad range of applications. At the energy-dispersive EXAFS beamline of the ESRF, ID24, the recently achieved 5 x 5 microm focal spot combined with fast acquisition has allowed complex and non-uniform samples to be mapped and images to be obtained(More)
Spray dried salbutamol sulphate and salbutamol base particles are amorphous as a result of spray drying. As there is always the risk of recrystallization of amorphous material, the aim of this work is the evaluation of the temperature and humidity dependent recrystallization of spray dried salbutamol sulphate and base. Therefore in-situ Powder X-ray(More)
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