Reproducibility and off-stoichiometry issues in nickelate thin films grown by pulsed laser deposition

Abstract

Rare-earth nickelates are strongly correlated oxides displaying a metal-to-insulator transition at a temperature tunable by the rare-earth ionic radius. In PrNiO${}_3$ and NdNiO${}_3$, the transition is very sharp and shows an hysteretic behavior akin to a first-order transition. Both the temperature at which the transition occurs and the associated resistivity change are extremely sensitive to doping and therefore to off-stoichiometry issues that may arise during thin film growth. Here we report that strong deviations in the transport properties of NdNiO${}_3$ films can arise in films grown consecutively under nominally identical conditions by pulsed laser deposition; some samples show a well-developed transition with a resistivity change of up to five orders of magnitude while others are metallic down to low temperatures. Through a detailed analysis of \textit{in-situ} X-ray photoelectron spectroscopy data, we relate this behavior to large levels of cationic off-stoichoimetry that also translate in changes in the Ni valence and bandwidth. Finally, we demonstrate that this lack of reproducibility can be remarkably alleviated by using single-phase NdNiO${}_3$ targets.

References in corpus (5)

• Physics of ultrathin films and heterostructures of rare earth nickelates
• Ground state oxygen holes and the metal-insulator transition in the negative charge transfer rare-earth nickelates
• Hybridization-controlled charge transfer and induced magnetism at correlated oxide interfaces
• Strain-mediated metal-insulator transition in epitaxial ultra-thin films of NdNiO3
• Key role of lattice symmetry in the metal-insulator transition of NdNiO3 films

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• Impact of Cation Stoichiometry on the Crystalline Structure and Superconductivity in Nickelates
• Synthesis and electronic properties of Nd${}_{n+1}$Ni${}_n$O${}_{3n+1}$ Ruddlesden-Popper nickelate thin films
• Synthesis of infinite-layer nickelates and influence of the capping-layer on magnetotransport
• Superconductivity in PrNiO2 infinite-layer nickelates
• Epitaxial growth of Ruddlesden-Popper neodymium nickelates Nd${}_{n+1}$Ni${}_n$O${}_{3n+1}$ ($n$ = 1-5)
• Synthesis of thin film infinite-layer nickelates by atomic hydrogen reduction: clarifying the role of the capping layer
• Probing photo-induced rearrangements in the NdNiO${}_3$ magnetic spiral with polarization-sensitive ultrafast resonant soft x-ray scattering
• Thin-film aspects of superconducting nickelates
• Freestanding perovskite and infinite-layer nickelate membranes