Related papers: Stable magnesium peroxide at high pressure
The chemical composition of a planetary body reflects its starting conditions modified by numerous processes during its formation and geological evolution. Measurements by X-ray, gamma-ray, and neutron spectrometers on the MESSENGER…
We report that calculating the Gibbs free energy of the alpha-Al_2O_3 (0001) surfaces in equilibrium with a realistic environment containing both oxygen and hydrogen species is essential for obtaining theoretical predictions consistent with…
A recent report [Kiguchi {\it et al.}, Phys. Rev. B {\bf 68}, 115402 (2003)] that the (111) surface of 5 MgO layers grown epitaxially on Ag(111) becomes metallic to reduce the electric dipole moment raises a question of what will happen…
The Solar System harbors deep unresolved mysteries despite centuries-long study. A highly intriguing case concerns anomalous non-dipolar and non-axisymmetric magnetic fields of Uranus and Neptune that have long eluded explanation by the…
Metastable superconductivity at \approx 50 K in the interfaces formed by metallic and oxidized magnesium (MgO) has been observed by ac magnetic susceptibility and electrical resistance measurements. The superconducting interfaces have been…
The geological conundrum of sulfur excess refers to the finding that predicted amounts of sulfur, in the form of SO2, discharged in volcanic eruptions much exceeds the sulfur available for degassing from the erupted magma. Exploring the…
We have used density-functional-theory methods and the ab initio random structure searching (AIRSS) approach to predict stable structures and stoichiometries of mixtures of iron and oxygen at high pressures. Searching was performed for 12…
MgB2 samples prepared by solid-state reaction were investigated using high-resolution transmission electron microscopy (HREM), X-ray energy-dispersive spectroscopy (EDX), electron energy-loss spectroscopy (EELS), and energy-filtered…
The electronic, the thermal, and the optical properties of hexagonal MgX monolayers (where X=C, N, and O) are investigated via first principles studies. Ab-initio molecular dynamic, AIMD, simulations using NVT ensembles are performed to…
Pressure significantly modifies the microscopic interactions in condense phase, leading to new patterns of bonding and unconventional chemistry. Both argon and xenon possess closed-shell electronic structures, which renders them chemically…
The effects of pressure on the crystal structure of the three known polymorphs of magnesium sulfate have been theoretically study by means of DFT calculations up to 45 GPa. We determined that at ambient conditions gamma MgSO4 is an unstable…
Using a fast and accurate neural network potential we are able to systematically explore the energy landscape of large unit cells of bulk magnesium oxide with the minima hopping method. The potential is trained with a focus on the…
The most abundant type of planet discovered in the Galaxy has no analogue in our Solar System and is believed to consist of a rocky interior with an overlying thick H2 dominated envelope. Models have predicted that the reaction between the…
Using density-functional theory (DFT) we calculate the Gibbs free energy to determine the lowest-energy structure of a RuO_2(110) surface in thermodynamic equilibrium with an oxygen-rich environment. The traditionally assumed stoichiometric…
Oxygen-isotope effects on the intrinsic resistivity have been studied in high-quality epitaxial thin films of La_{0.75}Ca_{0.25}MnO_{3} and Nd_{0.7}Sr_{0.3}MnO_{3}. We found that the residual resistivity \rho_{o} increases by about 15(3)%…
Understanding the behavior of the water-ammonia system at high pressure-high temperature conditions is important for modeling the internal dynamics of exoplanet icy mantles. Conventionally, mixtures of ammonia hemihydrate AHH (2:1…
Polynitrogen molecules represent the ultimate high energy-density materials as they have a huge potential chemical energy originating from their high enthalpy. However, synthesis and storage of such compounds remain a big challenge because…
Ferropericlase (Mg,Fe)O is a major lower mantle mineral, and studying its properties is a fundamental step toward understanding the Earth's interior. Here, we performed a first-principles investigation on the properties of iron as an…
The paper presents ab initio results on the structural phase stability of beryllium and magnesium crystals under high and ultrahigh pressures (multi-terapascal regime). Magnesium is shown to undergo a number of structural transformations…
Using evolutionary crystal structure prediction algorithm USPEX, we identify the compositions and crystal structures of stable compounds in the Fe-S system at pressures in the range 100-400 GPa. We find that at pressures of the Earth's…