Superconductivity in Cubic La3Al with Interstitial Anionic Electrons

Abstract We observed superconductivity in a cubic La 3 Al single crystal that exhibits metallic behavior in the normal state without an observable structural transition and enters the superconducting state below T c ∼ 6.32 K. Detailed characterization and analysis indicate that cubic La 3 Al is a bulk type-II BCS superconductor. Moreover, theoretical calculations show that it can host interstitial anionic electrons located at the body center of the cubic unit cell, which confirms electron–phonon coupling as the superconducting mechanism. Therefore, cubic La 3 Al can be considered as a novel electride superconductor.