Superconductivity and thermodynamic properties of MPb7 (M=Al, Mg) compounds: A first principles study

In this work, the superconductivity and thermodynamic properties of MPb7 (M = Al and Mg) have been investigated using density functional theory (DFT), general gradient approximation (GGA), and the Debye model. The mechanical, dynamic, and thermodynamic stability of the compounds have been achieved using cohesive energy, phonon, and thermodynamic results. Moreover, the calculations without spin–orbit coupling exhibit the maximum critical temperature (Tc) of 7.51 K and 7.12 K for AlPb7 and MgPb7, respectively. In addition, by considering spin–orbit coupling the maximum critical temperature of 7.26 K and 7.13 K have been obtained for AlPb7 and MgPb7, respectively. These high critical temperatures offer good superconductors, and because they contain Al and Mg elements which are environment-friendly and low-cost production they could be suggestible for superconductivity industries.