Amorphous silica-like carbon dioxide.

摘要: High pressure modifies the interatomic and intermolecular interactions in condensed matter, profoundly altering physical chemical properties of materials. This is dramatically demonstrated a newly discovered form carbon dioxide, dubbed a-carbonia. nonmolecular amorphous dioxide high modification CO2 molecular solid. It glassy material, homologous to silica (SiO2) germania (GeO2). The discovery could initiate new research areas solid-state chemistry light elements. Among group IV elements, only forms stable double bonds with oxygen at ambient conditions. At variance germania, non-molecular single-bonded crystalline phase V, exists pressure1,2,3,4,5,6,7,8,9. (a-SiO2) (a-GeO2) are well known conditions; however, amorphous, has so far been described as result first-principles simulations9. Here we report synthesis an silica-like a-CO2, which call ‘a-carbonia’. compression III between 40 48 GPa room temperature initiated transformation phase. Infrared spectra measured temperatures up 680 K show progressive formation C–O single simultaneous disappearance all signatures. Furthermore, state-of-the-art Raman synchrotron X-ray diffraction measurements on temperature-quenched samples confirm character material. Comparison vibrational data for a-SiO2 a-GeO2, structure factor calculated a-CO2 sample obtained by dynamics9, shows that structurally other glasses. We therefore conclude class archetypal network-forming disordered systems, including a-SiO2, a-GeO2 water, must be extended include a-CO2.