Primitive noble gases sampled from ocean island basalts cannot be from the Earth's core.

Noble gas isotopes in plumes require a source of primitive volatiles largely isolated in the Earth for 4.5 Gyrs. Among the proposed reservoirs, the core is gaining interest in the absence of robust geochemical and geophysical evidence for a mantle source.

Atomic transport properties of liquid iron at conditions of planetary cores.

Atomic transport properties of liquid iron are important for understanding the core dynamics and magnetic field generation of terrestrial planets. Depending on the sizes of planets and their thermal histories, planetary cores may be subject to quite different pressures (P) and temperatures (T). However, previous studies on the topic mainly focus on the P-T range associated with the Earth's outer core; a systematic study covering conditions from small planets to massive exoplanets is lacking.

Anisotropic diffusion creep in postperovskite provides a new model for deformation at the core-mantle boundary.

The lowermost portion of Earth's mantle (D″) above the core-mantle boundary shows anomalous seismic features, such as strong seismic anisotropy, related to the properties of the main mineral MgSiO postperovskite. But, after over a decade of investigations, the seismic observations still cannot be explained simply by flow models which assume dislocation creep in postperovskite. We have investigated the chemical diffusivity of perovskite and postperovskite phases by experiment and ab initio simulation, and derive equations for the observed anisotropic diffusion creep.

The thermal expansion of gold: point defect concentrations and pre-melting in a face-centred cubic metal.

On the basis of computer simulations, pre-melting phenomena have been suggested to occur in the elastic properties of hexagonal close-packed iron under the conditions of the Earth's inner core just before melting. The extent to which these pre-melting effects might also occur in the physical properties of face-centred cubic metals has been investigated here under more experimentally accessible conditions for gold, allowing for comparison with future computer simulations of this material. The thermal expansion of gold has been determined by X-ray powder diffraction from 40 K up to the melting point (1337 K).

The phase diagrams of KCaF and NaMgF by ab initio simulations.

ABF compounds have been found to make valuable low-pressure analogues for high-pressure silicate phases that are present in the Earth's deep interior and that may also occur in the interiors of exoplanets. The phase diagrams of two of these materials, KCaF and NaMgF, have been investigated in detail by static ab initio computer simulations based on density functional theory. Six ABF polymorphs were considered, as follows: the orthorhombic perovskite structure (GdFeO-type; space group ); the orthorhombic CaIrO structure (; commonly referred to as the "post-perovskite" structure); the orthorhombic SbS and LaS structures (both ); the hexagonal structure previously suggested in computer simulations of NaMgF (6/); the monoclinic structure found to be intermediate between the perovskite and CaIrO structures in CaRhO (2/).