Prediction of a three-dimensional carbon allotrope moC12 with one-dimensional metallicity, superconductivity and mechanical anisotropy.

The search for carbon allotropes with exotic electrical and mechanical properties is one of frontier topics in materials science. In this work, we proposed a carbon allotrope, namely moC₁₂, with unexpected one-dimensional metallicity, superconductivity and mechanical anisotropy via first-principles calculations. This novel carbon allotrope contains 12 atoms in its unit cell with interatomic connections via sp²–sp³ hybridization, forming a three-dimensional spatial sandwich panel anisotropic structure. The dynamic and mechanical stability of the new structure in the ambient state is demonstrated. The one-dimensional conductivity originates from the one-dimensional conductive channel constituted between the sp²-hybridized atoms, while in other directions this conductive channel is interrupted by the residual sp³-hybridized carbon atoms. Moreover, moC₁₂ is superconductive, with a superconducting critical temperature of 2.14 K. The unique three-dimensional spatial sandwich panel anisotropic structure endows moC₁₂ with excellent toughness and also exhibits intense mechanical anisotropy including elasticity and tensile stress–strain. The distinctive conductive and mechanical natures make moC₁₂ a potential material for probe in the direction measuring. [ABSTRACT FROM AUTHOR]