The Physical Properties of a Novel Carbon Allotrope in Tetragonal Symmetry

A novel sp(3) + sp(2) hybridized carbon allotrope in the P4/mmm phase, denoted as tP48 carbon, is proposed and predicted according to density functional theory. The tP48 carbon allotrope is mechanically, dynamically, and thermodynamically stable. The bulk modulus, B, of tP48 carbon is slightly larger than that of other carbon allotropes in the tP family. Of the tP family of carbon materials, tP48 carbon exhibits the greatest anisotropy in terms of its Young's modulus, E, Poisson's ratio, v, and shear modulus, G. In regards to its electronic band structure, tP48 carbon is an indirect semiconductor material with a band gap of 1.516 eV. The XRD characteristics of tP48 carbon are also studied in this work, with the associated characteristics found to be of guiding significance for determining the structure of tP48 carbon in subsequent experiments.