The superconductivity and electron-doping effect in MgP<sub>2</sub>H<sub>14</sub> hydrides.

Abstract

Room temperature superconductivity has become the tireless pursuit of scientists due to its epoch-making significance. Inspired by the recently predicted high superconductivity in LiP₂H₁₄, we identify a new superconductor MgP₂H₁₄ by substituting Li with Mg and prove its stability. The superconducting critical temperature (<i>T</i> _c) and electron-phonon coupling (EPC) parameters (<i>λ</i>) of MgP₂H₁₄ under 280 GPa are predicted to be ∼166 K and ∼1.65, respectively; the high superconductivity of MgP₂H₁₄ mainly arises from the strong electron-phonon interaction between H 1<i>s</i> electrons and the H-associated vibration. Furthermore, in hydrogen-based superconductors, the hydrogen sublattice will gain more electrons by doping extra metal atoms or replacing the original metals with higher valence electrons metals. However, if these electrons do not form newly occupied states on the hydrogen energy level near the Fermi level, the superconductivity will not improve further. Our findings provide clues for designing and modulating the superconductivity.