Pressure-induced Sc-intercalated graphene nanoribbon with ambient-pressure superconductivity

Abstract Exploration of carbon-based superconductors has attracted sustained interest over the past decades. Herein, we systematically investigate the Sc-C system across the pressure range of 0-100 GPa through extensive computational structure searches. Two novel carbon-rich phases Sc 2 C 3 and ScC 2 are predicted to be thermodynamically stable at high pressure. Both phases feature a unique structure of Sc-intercalated graphene nanoribbon. Further electron-phonon coupling calculations predict the superconducting critical temperatures of ~3 K for Sc 2 C 3 and ~11 K for ScC 2 at ambient pressure. Analysis shows that the coupling between Sc d -orbital electrons and Sc-associated phonon modes induced potential superconductivity. These results enrich the chemistry of scandium carbides and suggest a new strategy for carbon-based superconductors through metal-intercalated graphene nanoribbon.