Superconductivity in cubic La₃Al with interstitial anionic electrons

We report the observation of superconductivity in cubic La₃Al single crystal. It shows a metallic behavior at a normal state without observable structural transition and enters the superconducting state below T_c ~ 6.32 K. Detailed characterizations and analysis indicate that cubic La₃Al is a bulk type-II BCS superconductor. Moreover, theoretical calculations show that it can host interstitial anionic electrons, which are located at the body center of cubic unit cell, and confirm the electronphonon coupling as the superconducting mechamism. Thus, cubic La₃Al can be regarded as an novel electride superconductor.