Extended Data Fig. 2: Post-annealing.
From: Ambient-pressure superconductivity onset above 40 K in (La,Pr)3Ni2O7 films
a, Resistivity-versus-temperature curves of a 3UC La2.85Pr0.15Ni2O7/SrLaAlO4 sample before and after pure ozone flow annealing. This is a different sample from the one shown in Figs. 1 and 2 in the main text. b, X-ray diffraction (XRD) of the same sample shown in (a) before and after pure ozone flow annealing. c, Resistivity-temperature curves for La2.85Pr0.15Ni2O7 films on SrLaAlO4 substrates with different annealing conditions as follows. Sample 1 (3UC): 400 °C for 30 mins, with an O3 pressure of 1.57 × 10−1 mbar. Sample 2 (3UC): 500 °C for 30 mins, with an O3 pressure of 1.52 × 10−1 mbar. Sample 3 (3UC): 700 °C for 30 mins, with an O3 pressure of 1.10 × 10−1 mbar. Sample 4 (3UC): 600 °C for 30 mins, with an O3 pressure of 1.00 × 10−1 mbar. Sample 5 (3UC): 600 °C for 30 mins, with an O3 pressure of 1.38 × 10−1 mbar. Sample 6 (3UC): 600 °C for 30 mins, with an O3 pressure of 1.38 × 10−1 mbar. Sample 7 (3UC): 600 °C for 30 mins, with an O3 pressure of 1.30 × 10−1 mbar. Sample 8 (6UC): 700 °C for 30 mins, with an O3 pressure of 1.67 × 10−1 mbar. Sample 9 (6UC): 700 °C for 30 mins, with an O3 pressure of 2.03 × 10−1 mbar. The growth conditions for all films were identical as described in the methods section.
