First-principles prediction of superconductivity in MgB3C3

• DOI: 10.1103/physrevb.107.134502
• Publication Date: 2023-04-04T21:33:18Z
• Authors: Truong-Tho Pham; Duc-Long Nguyen
• Keywords: Superconductivity (cond-mat.supr-con); Condensed Matter - Superconductivity; FOS: Physical sciences

From first-principles density functional theory calculations, we propose hexagonal layered MgB$_3$C$_3$ as a potential phonon-mediated superconductor at 59 K, which is far higher than the superconductivity of MgB$_2$ ($\approx$ 39 K). The energetically and dynamically stable ambient pressure in \textit{P-62m} structure with c/a $\approx$ 0.79 forms stacks honeycomb B-C layers Mg space filler. Band calculations indicate that bands Fermi level derive mainly from B C orbitals two $\sigma$- $\pi$ both contribute to total state. are found be strongly couple out-of-plane acoustic phonon mode, while $\sigma$ coupled in-plane bond-stretching optical E$^{\prime} $ modes produces sizable MgB$_3$C$_3$.