Extended Data Fig. 1: Growth.
From: Ambient-pressure superconductivity onset above 40 K in (La,Pr)3Ni2O7 films
a, Schematic of synthesizing (La,Pr)3Ni2O7 on SrLaAlO4 with gigantic-oxidative atomically layer-by-layer epitaxy (GOALL-Epitaxy). b and c, RHEED oscillations and patterns of La3Ni2O7 and La2.85Pr0.15Ni2O7 growth on SrLaAlO4. Blue and orange blocks represent the growth of LaOx/(La0.95Pr0.05)Ox and NiOx layer, respectively. d-g, Time evolution of RHEED pattern during the growth of La2.85Pr0.15Ni2O7 film on SrLaAlO4 substrate. RHEED pattern of the substrate SrLaAlO4 (d), 1 unit cell of La2.85Pr0.15Ni2O7 (e), 2 unit cells (f) and 3 unit cells (g), respectively along [100] direction. Red solid line in (d) represents the intensity profile, which is obtained by integrating the intensity vertically in the rectangular area marked with red dashed line. h, Evolution of the distance between 00 and 01 diffraction spots, which is determined by the peak position of the intensity profile and the error bar is calculated by the FWHM of the peak.
