Reversible elastic deformation of functionalized sp2 carbon at pressures of up to 33 GPa

We show that sp2 carbon bonded to silicon and oxygen can withstand reversible elastic deformation at pressures of up to 33 GPa. These experiments were carried out in a diamond anvil cell. In-situ Raman spectroscopy was employed to record the reversibility of elastic deformation by measuring the movement in the D and G peaks of carbon. Above 33 GPa the material, a silicon oxycarbide, transforms into an unidentified state which is retained upon unloading down to ambient pressure. Thermodynamical analysis suggests that the material could have transformed into a crystalline state at these ultrahigh pressures, driven by mechanical work.