Synchrotron Mossbauer spectroscopic study of ferropericlase at high pressures and temperatures

Synchrotron Mössbauer spectroscopic study of ferropericlase at high pressures and temperatures

The electronic spin state of Fe2+ in ferropericlase, (Mg0.75Fe0.25)O, transitions from a high-spin (spin unpaired) to low-spin (spin paired) state within the Earth’s mid-lower mantle region. To better understand the local electronic environment of high-spin Fe2+ ions in ferropericlase near the transition, we obtained synchrotron Mössbauer spectra (SMS) of (Mg0.75,Fe0.25)O in externally heated a...

Spectroscopic study of mutual solubilities of water and benzene at high temperatures and pressures.

Near-infrared and ultraviolet absorption of water-benzene mixtures has been measured at temperatures and pressures in the ranges of 323-673 K and 50-400 bar, respectively. Concentrations of water and benzene in both the water-rich phase and the benzene-rich phase of the mixtures were obtained from absorption intensities of near-infrared bands of water and benzene and ultraviolet bands of benzen...

Structural changes in liquid Fe at high pressures and high temperatures from Synchrotron X-ray Diffraction

– High-energy synchrotron X-ray diffraction measurements on liquid iron in the vicinity of the δ-γ-liquid triple point (to 2300 K and 5 GPa) reveal significant changes in the structure of the liquid upon increasing pressure and temperature. The second and third neighbor shells in the g(r) shift to shorter distances and develop new structure with increasing pressure. The results can be interpret...

Fluids at high pressures and temperatures

With high pressures, supercritical fluids can be studied over a very wide range of density. Fluids with strongly interacting polar molecules for example water are of particular interest. Results for several thermophysical properties are discussed. Density, dielectric constant and self—ionization of water have been determined or predicted to 1000 °C. Beyond 20 GPa very hot water appears to becom...

Electrical conductivity of wadsleyite at high temperatures and high pressures