Pressure Stabilized Lithium-Aluminum Compounds with BothSuperconducting and Superionic Behaviors br

Superconducting and superionic behaviors have physically intriguing dynamic properties of electronsand ions, respectively, both of which are conceptually important and have great potential for practicalapplications. Whether these two phenomena can appear in the same system is an interesting and importantquestion. Here, using crystal structure predictions and first-principle calculations combined with machinelearning, we identify several stable Li-Al compounds with electride behavior under high pressure, and wefind that the electronic density of states of some of the compounds has characteristics of the two-dimensional electron gas. Among them, we estimate that Li6Al at 150 GPa has a superconducting transitiontemperature of around 29 K and enters a superionic state at a high temperature and wide pressure range. Thediffusion in Li6Al is found to be affected by an electride and attributed to the atomic collective motion. Ourresults indicate that alkali metal alloys can be effective platforms to study the abundant physical propertiesand their manipulation with pressure and temperature

Automated summary

In this study, we identified stable Li-Al compounds with electride behavior under high pressure using crystal structure predictions and first-principle calculations combined with machine learning. Some of these compounds exhibited characteristics of a two-dimensional electron gas. We found that Li6Al at 150 GPa has a superconducting transition temperature of around 29 K and enters a superionic state at a high temperature and wide pressure range.