Phonon-mediated superconductivity in Mg intercalated bilayer borophenes

Using first-principles calculations, we investigate the structural, electronic and superconducting properties of Mg intercalated bilayer borophenes BxMgBx (x = 2-5). Remarkably, B2MgB2 and B4MgB4 are predicted to exhibit good phonon-mediated superconductivity with a high transition temperature (T-c) of 23.2 K and 13.3 K, respectively, while B4MgB4 is confirmed to be more practical based on the analyses of its stability. The densities of states of in-plane orbitals at the Fermi level are found to be dominant at the superconducting transition temperature in Mg intercalated bilayer borophenes, providing an effective avenue to explore Mg-B systems with high T(c)s.