The family of rare-earth nickelates (RNiO3. R = La, Pr, ..., Lu) show a sharp metal-insulator transition from a paramagnetic metal to an anti-ferromagnetic insulator. The only exception is LaNiO3...Show moreThe family of rare-earth nickelates (RNiO3. R = La, Pr, ..., Lu) show a sharp metal-insulator transition from a paramagnetic metal to an anti-ferromagnetic insulator. The only exception is LaNiO3 which is a paramagnetic metal even at low temperatures. Thin films of LaNiO3 do show a metal-insulator transition when reducing the film thickness to only a few unit cells. In this study we track the electronic structure of (001) oriented LaNiO3 thin films as they go from a metallic to an insulating state. We observe this transition occurring at a thickness of 4 unit cells. The very high resolution of our ARPES set-up allows us to resolve the inelastic mean free path changing with film thickness. We find that the mean free path mimics the reported resistivity behaviour. We also find a pseudogap opening in the insulating state.Show less
