Stability of superconducting Nd0.8Sr0.2NiO2 thin films

The discovery of superconducting states in the nickelate thin film with infinite-layer structure has paved a new way for studying unconventional superconductivity. So far, research in this field is still very limited due to difficulties in sample preparation. Here we report the successful preparation of the superconducting state of Nd0.8Sr0.2NiO2 thin film (Tc = 8.0–11.1 K) and study the stability of such films in the ambient environment, water, and under electrochemical conditions. Our work demonstrates that the superconducting state of Nd0.8Sr0.2NiO2 is remarkably stable, which can last for at least 47-day continuous exposure to air at 20°C and 35% relative humidity. We also show that the superconductivity disappears after being immersed in de-ionized water at room temperature for 5 h. Surprisingly, it can also survive under ionic liquid gating conditions with an applied voltage of about 4 V, which is even more stable than conventional perovskite complex oxides.