Hybridization-controlled charge transfer and induced magnetism at correlated oxide interfaces

Abstract

At interfaces between conventional materials, band bending and alignment are classically controlled by differences in electrochemical potential. Applying this concept to oxides in which interfaces can be polar and cations may adopt a mixed valence has led to the discovery of novel two-dimensional states between simple band insulators such as LaAlO3 and SrTiO3. However, many oxides have a more complex electronic structure, with charge, orbital and/or spin orders arising from correlations between transition metal and oxygen ions. Strong correlations thus offer a rich playground to engineer functional interfaces but their compatibility with the classical band alignment picture remains an open question. Here we show that beyond differences in electron affinities and polar effects, a key parameter determining charge transfer at correlated oxide interfaces is the energy required to alter the covalence of the metaloxygen bond. Using the perovskite nickelate (RNiO3) family as a template, we probe charge reconstruction at interfaces with gadolinium titanate GdTiO3. X-ray absorption spectroscopy shows that the charge transfer is thwarted by hybridization effects tuned by the rare-earth (R) size. Charge transfer results in an induced ferromagnetic-like state in the nickelate, exemplifying the potential of correlated interfaces to design novel phases. Further, our work clarifies strategies to engineer two-dimensional systems through the control of both doping and covalence.

arXiv commentWork supported by ERC Consolidator grant MINT (Contract No. 615759)

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Cited by in corpus (27)

• Structurally Triggered Metal-Insulator Transition in Rare-Earth Nickelates
• Reconciling the ionic and covalent pictures in rare-earth nickelates
• Band alignment and charge transfer in complex oxide interfaces
• Charge transfer driven emergent phenomena in oxide heterostructures
• Charge transfer in iridate-manganite superlattices
• Complex magnetic order in nickelate slabs
• Reproducibility and off-stoichiometry issues in nickelate thin films grown by pulsed laser deposition
• Selectively controlled ferromagnets by electric fields in van der Waals ferromagnetic heterojunctions
• Orbital engineering in nickelate heterostructures driven by anisotropic oxygen hybridization rather than orbital energy levels
• Hydrogen induced electronic transition within correlated perovskite nickelates with heavy rare-earth composition
• Control of magnetic anisotropy by orbital hybridization in (La0.67Sr0.33MnO3)n/(SrTiO3)n superlattice
• Metal-insulator-metal transition in NdNiO3 films capped by CoFe2O4
• (LaTiO${}_3$)${}_n$/(LaVO${}_3$)${}_n$ as a model system for unconventional charge transfer and polar metallicity
• Superconductor to Mott insulator transition in YBa${}_2$Cu${}_3$O${}_7$/LaCaMnO${}_3$ heterostructures
• Emergent c-axis magnetic helix in manganite-nickelate superlattices
• Origin of the different electronic structure of Rh- and Ru-doped Sr2IrO4
• Unraveling p-type and n-type interfaces in Superconducting Infinite-Layer Nickelate thin films
• Visualizing quantum phenomena at complex oxide interfaces: an atomic view from scanning transmission electron microscopy
• Growth and characterization of large (Y,La)TiO${}_3$ and (Y,Ca)TiO${}_3$ single crystals
• Band-Engineered LaFeO${}_3$-LaNiO${}_3$ Thin Film Interfaces for Electrocatalysis of Water
• Determination of the local structure of Sr${}_{2-x}$M${}_x$IrO${}_4$ (M = K, La) as a function of doping and temperature
• PERSPECTIVE: Emergent phases in rare earth nickelate heterostructures
• Local polarization and valence distribution in LaNiO3/LaMnO3 heterostructures
• Optical spectra of rare-earth nickelates
• Emerging interfacial magnetization in isovalent manganite heterostructures driven by octahedral coupling
• Interfacial Multiferroics of TiO2/PbTiO3 Heterostructure Driven by Ferroelectric Polarization Discontinuity
• Emergence of interfacial magnetism in strongly-correlated nickelate-titanate superlattices