Fig. 2: Thin film characterization.

a RHEED intensity evolution during PLD growth of LaNiO3−δ on a (001)-oriented SrTiO3 substrate. Inset: RHEED pattern after growth. b X-ray diffractogram of representative 20 nm LaNiO3−δ films in (001), (110) and (111) orientation. Each diffractogram shows the most intense substrate and film peaks for the given orientation. c AFM scans of the same films. The root-mean-square roughness is below 350 pm for all films.