Related papers: Stable magnesium peroxide at high pressure
Sodium chloride (NaCl), or rocksalt, is well characterized at ambient pressure. Due to the large electronegativity difference between Na and Cl atoms, it has highly ionic chemical bonding, with stoichiometry 1:1 dictated by charge balance,…
We have performed a combined experimental and theoretical study of ethane and methane at high pressures up to 120 GPa at 300 K using x-ray diffraction and Raman spectroscopy and the USPEX ab-initio evolutionary structural search algorithm,…
In this work, global search for crystal structures of ternary Mg-Sc-H hydrides (Mg$_x$Sc$_y$H$_z$) under high pressure ($100 \le P \le 200$ GPa) were performed using the evolutionary algorithm and first-principles calculations. Based on…
The possible redox (oxidation reduction) chemical methods for precisely determining the oxygen content in the perovskite manganites including hole-doped La1-xCaxMnOy and electron-doped La1-xTexMnOy compounds are described. For manganites…
Despite the fact that the terrestrial planets formed from the protoplanetary disk, their compositions show marked departures from that of solar nebula condensates. Metallic cores fix oxygen fugacities ($f$O$_2$s) of the planets to 5…
The structure, lattice dynamics and mechanical properties of the magnesium hydroxide have been investigated with static density functional theory calculations as well as \it {ab initio} molecular dynamics. The hypothesis of a superstructure…
For most planets in the range of radii from 1 to 4 R$_{\oplus}$, water is a major component of the interior composition. At high pressure H${}_{2}$O can be solid, but for larger planets, like Neptune, the temperature can be too high for…
Using evolutionary crystal structure prediction algorithm USPEX, we showed that at pressures of the Earth's lower mantle CaAl2O4 is the only stable calcium aluminate. At pressures above 7.0 GPa it has the CaFe2O4-type structure and space…
Recently, it has been shown that under pressure, unexpected and counterintuitive chemical compounds become stable. Laser shock experiments (A. Rode, unpublished) on alumina (Al2O3) have shown non-equilibrium decomposition of alumina with…
Silicon and Mg in differentiated rocky bodies exhibit heavy isotope enrichments that have been attributed to evaporation of partially or entirely molten planetesimals. We evaluate the mechanisms of planetesimal evaporation in the early…
Chemical compositions of giant planets provide a means to constrain how and where they form. Traditionally, super-stellar elemental abundances in giant planets were thought to be possible due to accretion of metal-rich solids. Such…
Crystal growth experiments (micro-pulling down or Czochralski methods, respectively) and DTA/TG measurements with Fe2+ containing olivines (fayalite--forsterite solid solution) and with FeO (wustite) are performed. For both substances the…
We tune the thermodynamics of hydrogen absorption in Mg by means of elastic clamping. The loading isotherms measured by hydrogenography show that Mg films covered with Mg-alloy-forming elements, such as Pd and Ni, have hydrogen plateau…
Series of metastable Me1-xZnxO solid solutions (Me = Ni2+, Co2+, Fe2+, Mn2+) with the rocksalt (rs) crystal structure have been synthesized from the binary oxides by quenching from 7.7 GPa and 1450-1650 K. Phase composition of the samples,…
The free energies of vacancy pair formation and migration in MgO were computed via molecular dynamics using free-energy integrations and a non-empirical ionic model with no adjustable parameters. The intrinsic diffusion constant for MgO was…
C-H-N-O system is central for organic chemistry and biochemistry, and plays a major role in planetary science (dominating the composition of "ice giants" Uranus and Neptune). The inexhaustible chemical diversity of this system at normal…
Hydrogen in its metallic form is the most common material in our solar system, found under the extreme pressure and temperature conditions found in giant planets. Such conditions are inaccessible to experiment and consequently, theoretical…
The carbon to oxygen ratio in a protoplanetary disk can have a dramatic influence on the compositions of any terrestrial planets formed. In regions of high C/O, planets form primarily from carbonates and in regions of low C/O, the ratio of…
The high-pressure phases of solid hydrogen are of fundamental interest and relevant to the interior of giant planets; however, knowledge of these phases is far from complete. Particle swarm optimization (PSO) techniques were applied to a…
First principles electronic structure calculations based on density functional theory have been used to study the thermodynamic, structural and transport properties of solid solutions and liquid alloys of iron and oxygen at Earth's core…