Search results for "Ringwoodite"

showing 4 items of 4 documents

The pressure-induced ringwoodite to Mg-perovskite and periclase post-spinel phase transition: a Bader’s topological analysis of the ab initio electro…

2011

In order to characterize the pressure-induced decomposition of ringwoodite (c-Mg2SiO4), the topological analysis of the electron density q(r), based upon the theory of atoms in molecules (AIM) developed by Bader in the framework of the catastrophe theory, has been performed. Calculations have been carried out by means of the ab initio CRYSTAL09 code at the HF/DFT level, using Hamiltonians based on the Becke- LYP scheme containing hybrid Hartree– Fock/density functional exchange–correlation terms. The equation of state at 0 K has been constructed for the three phases involved in the post-spinel phase transition (ringwoodite -> Mg-perovskite + periclase) occurring at the transition zone–lower…

Bader’s topological analysisElectron densityEquation of statePhase transitionRingwoodite Post-spinel phase transition Bader’s topological analysis Ab initio Catastrophe theory Critical pointsChemistryCatastrophe theoryAtoms in moleculesRingwooditeAb initioCritical pointsHartreeengineering.materialTopologyRingwoodite; Post-spinel phase transition; Bader’s topological analysis; Ab initio; Catastrophe theory; Critical pointsPost-spinel phase transitionRingwooditeGeochemistry and PetrologyBader’s topological analysiAb initioengineeringGeneral Materials SciencePerovskite (structure)
researchProduct

High-pressure crystal structure investigation of synthetic Fe2SiO4 spinel.

2011

AbstractThe crystal structure of Fe2SiO4 spinel at room temperature was investigated at seven different pressures by X-ray diffraction, using a diamond anvil cell to examine the influence of Fe substitution on ringwoodite behaviour at high pressure. The results compared with those of a pure Mg endmember show that the substitution of Fe into the spinel structure causes only small changes in the compression rate of coordination polyhedra and the distortion of the octahedron. The data show that the compression rate for the octahedron and tetrahedron in (Mg,Fe)2SiO4 can be considered statistically equal for FeO6 and MgO6, as well as for SiO4 in both the endmembers. This shows why almost identic…

Materials sciencehigh pressure; X-ray diffraction; single crystal; synthetic Fe2SiO4 spinel010504 meteorology & atmospheric scienceshigh pressure X-ray diffraction single crystal synthetic Fe2SiO4 spinelX ray diffractionSpinel550 - Earth sciencesCrystal structureengineering.material01 natural scienceshigh pressure; X ray diffraction; single crystal; synthetic Fe2SiO4 spinelX-ray diffractionCrystallographyRingwooditehigh pressureOctahedronsynthetic Fe2SiO4 spinelGeochemistry and PetrologyX-ray crystallographyengineeringTetrahedronsingle crystalSingle crystal0105 earth and related environmental sciencesSolid solution
researchProduct

A BADER’S TOPOLOGICAL APPROACH FOR THE CHARACTERIZATION OF PRESSURE INDUCED PHASE TRANSITIONS

2012

Ringwoodite Bader analysis Phase transitions topology
researchProduct

Characterization of the pressure induced Ringwoodite to Mg-perovskite+Mg-wuestite phase transition by Catastrophe Theory

2010

phase transition Ringwoodite Mg-perovskite Mg-wuestite Catastrophe Theory
researchProduct