Superconductivity in ordered LiBe alloy under high pressure: A first-principles study

The electronic, vibrational, and superconducting properties of LiBe alloy in the P21/m structure under pressure have been investigated using first-principles calculations. The calculated electron–phonon coupling (EPC) of LiBe with both linear response theory and the rigid muffin-tin approximation suggested that pairing electrons are mainly mediated by the Li low-lying phonon vibrations, and the increase of the Li EPC matrix element 〈Ii2〉 with pressure is responsible for the increased EPC parameter λλ. The application of the Allen–Dynes modified McMillan equation reveals high superconducting critical temperatures of 15.2 K at 80 GPa and 18.4 K at 100 GPa for P21/m LiBe.

► Relatively high superconducting temperatures were predicted for LiBe at high pressures.
► The origin of the superconductivity is revealed.
► The superconducting temperature increases with pressure.
► LiBe with P21/m structure is a potential high-temperature superconductor.