Amorphous silica-like carbon dioxide

  title={Amorphous silica-like carbon dioxide},
  author={Mario Santoro and Federico Aiace Gorelli and Roberto Bini and Giancarlo Ruocco and Sandro Scandolo and Wilson A. Crichton},
Among the group IV elements, only carbon forms stable double bonds with oxygen at ambient conditions. At variance with silica and germania, the non-molecular single-bonded crystalline form of carbon dioxide, phase V, only exists at high pressure. The amorphous forms of silica (a-SiO2) and germania (a-GeO2) are well known at ambient conditions; however, the amorphous, non-molecular form of CO2 has so far been described only as a result of first-principles simulations. Here we report the… 
Silicon carbonate phase formed from carbon dioxide and silica under pressure
It is shown that reactions occur at high pressures indicating that silica can behave in a manner similar to ionic metal oxides that form carbonates at room pressure, and the potential for synthesis of a class of previously uncharacterized materials is revealed.
Crystalline polymeric carbon dioxide stable at megabar pressures
Carbon dioxide is a widespread simple molecule in the Universe. In spite of its simplicity it has a very complex phase diagram, forming both amorphous and crystalline extended phases above 40 GPa.
Carbon substitution for oxygen in silicates in planetary interiors
It is suggested that significant (several percent) substitution of C for O could occur in more complex geological silicate melts/glasses in contact with graphite at moderate pressure and high temperature and may be thermodynamically far more accessible than C for Si substitution.
Carbon enters silica forming a cristobalite-type CO2–SiO2 solid solution
The synthesis of a crystalline CO2–SiO2 solid solution is reported by reacting carbon dioxide and silica in a laser-heated diamond anvil cell, showing that carbon enters silica and may modify the view on oxide chemistry.
Electronic structure of carbon dioxide under pressure and insights into the molecular-to-nonmolecular transition
Light is shed on the successive pressure-induced local structural changes and the molecular-to-nonmolecular transition of CO2 at room temperature by performing an in situ study of the local electronic structure using X-ray Raman scattering, aided by first-principle exciton calculations.
Solid-state chemistry: A glass of carbon dioxide
This newly discovered form of carbon dioxide, dubbed a-carbonia, is a glassy material, homologous to amorphous silica and germania, and could initiate new research areas in the solid-state chemistry of light elements.
High-pressure polymeric phases of carbon dioxide
The recently developed metadynamics method combined with ab initio calculations is employed to provide fundamental insight into recent experimental reports on carbon dioxide in the 60–80 GPa pressure region to find pressure-induced polymeric phases and their transformation mechanisms.
Phase diagram of carbonyl sulfide: An analogy to carbon dioxide and carbon disulfide
The application of pressure, internal or external, transforms molecular solids into nonmolecular extended network solids with diverse crystal structures and electronic properties, ranging from
Structure, Bonding, and Mineralogy of Carbon at Extreme Conditions
The nature and extent of Earth’s deep carbon cycle remains uncertain. This chapter considers high-pressure carbon-bearing minerals, including those of Earth’s mantle and core, as well as phases that
Physical and chemical transformations of highly compressed carbon dioxide at bond energies.
  • C. Yoo
  • Materials Science, Chemistry
    Physical chemistry chemical physics : PCCP
  • 2013
The pressure-induced transformations observed in highly compressed carbon dioxide are reviewed and chemistry perspectives on those molecular-to-non-molecular transformations that can be applied to other low-Z molecular solids at Mbar pressures where the compression energy rivals the chemical bond energies are presented.


Crystal structure of carbon dioxide at high pressure : "Superhard" polymeric carbon dioxide
The crystal structures of two molecular phases (I and III) and a polymeric phase (V) of CO2 have been investigated to 60 GPa. CO2-1 (Pa3) transforms to CO2-III (Cmca) at 12 GPa with almost no change
Single-bonded cubic form of nitrogen
The polymeric nitrogen with the theoretically predicted cubic gauche structure (cg-N) represents a new class of single-bonded nitrogen materials with unique properties such as energy capacity: more than five times that of the most powerfully energetic materials.
Quartzlike carbon dioxide: An optically nonlinear extended solid at high pressures and temperatures
An extended-solid phase, carbon dioxide phase V (CO2-V), was synthesized in a diamond anvil cell by laser heating the molecular orthorhombic phase, carbon dioxide phase III, above 40 gigapascals and
Theoretical investigation of high pressure phases of carbon dioxide
A theoretical analysis of the implications of this metamorphosis of carbon dioxide suggests the existence of a very hard phase of the stishovite type.
Linear carbon dioxide in the high-pressure high-temperature crystalline phase IV.
The claimed bent molecular geometry of CO2 in phase IV can be unambiguously ruled out and the structures of both phases II and IV have been identified as orthorhombic.
Pressure-induced amorphization of crystalline silica
The crystalline-to-amorphous transformation in the solid state is currently the subject of intense study. With the seminal discovery of amorphization of H2O ice I under pressure1, interest has
Spectroscopic Evidence for Pressure-Induced Coordination Changes in Silicate Glasses and Melts
Continuous and reversible coordination change in amorphous silicates explains the lack of observation of coordination changes in silicate glasses quenched from high pressure, the shallow melting slopes observed for mantle silicates at high pressures, and the possible presence of neutrally buoyant magmas deep within the terrestrial planets.
Crystal Structure of the High-Pressure Phase of Solid CO2
X-ray diffraction study of solid CO2 at room temperature has shown that the powder pattern of the high-pressure phase, which supersedes the low-pressure cubic Pa3 phase at about 10 gigapascals, is
High‐pressure infrared sepctra of ∝ ‐quartz, coesite, stishovite and silica glass
High-pressure infrared absorption spectra of α-quartz, coesite, stishovite, and SiO2 glass are consistent with the primary compression mechanism of the initially tetrahedrally bonded phases being the
Pressure-induced solid carbonates from molecular CO2 by computer simulation
A class of carbonates, involving special arrangements of CO4 tetrahedra, is found to be more stable than all the other silica-like polymorphs.