Visualization of Oxygen Vacancies and Self-doped Ligand Holes in La3Ni2O7-δ

Abstract

The recent discovery of superconductivity in La3Ni2O7-δ under high pressure with a transition temperature around 80 K has sparked extensive experimental and theoretical efforts. Several key questions regarding the pairing mechanism remain to be answered, such as the most relevant atomic orbitals and the role of atomic deficiencies. Here, we develop a new energy-filtered multislice electron ptychography technique, assisted with electron energy loss spectroscopy, to address these critical issues. Oxygen vacancies are directly visualized and are found to primarily occupy the inner apical sites, which have been proposed to be crucial to superconductivity. We precisely determine the nanoscale stoichiometry and its correlation to the oxygen K edge spectra, which reveals a significant inhomogeneity in the oxygen content and electronic structure within the sample. The spectroscopic results also unveil that stoichiometric La3Ni2O7 is in the charge-transfer regime, with holes that are self-doped from Ni sites into O sites. The outer apical oxygen is found to be less relevant to the low-energy physics and can be safely disregarded in theoretical models. These observations will assist in further development and understanding of superconducting nickelate materials. Our imaging technique for quantifying atomic deficiencies can also be widely applied in materials science and condensed matter physics.

24 pages, 4 figures, and 10 supplementary figures

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• Synthesis and electronic properties of Nd${}_{n+1}$Ni${}_n$O${}_{3n+1}$ Ruddlesden-Popper nickelate thin films
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Cited by in corpus (82)

• Orbital-Dependent Electron Correlation in Double-Layer Nickelate La3Ni2O7
• Ambient-pressure superconductivity onset above 40 K in bilayer nickelate ultrathin films
• Electronic and magnetic excitations in La${}_3$Ni${}_2$O${}_7$
• Structure responsible for the superconducting state in La3Ni2O7 at high pressure and low temperature conditions
• Normal and superconducting properties of La${}_3$Ni${}_2$O${}_7$
• Superconductivity in nickelate and cuprate superconductors with strong bilayer coupling
• Neutron Scattering Studies on the High-$T_c$ Superconductor La${}_3$Ni${}_2$O${}_{7-\delta }$ at Ambient Pressure
• Pressure-enhanced spin-density-wave transition in double-layer nickelate $L{a}_{3}N{i}_2{O}_{7-\delta }$
• Identification of the superconductivity in bilayer nickelate La${}_3$Ni${}_2$O${}_7$ upon 100 GPa
• Angle-resolved photoemission spectroscopy of superconducting (La,Pr)3Ni2O7/SrLaAlO4 heterostructures
• Effective model and $s_{\pm }$-wave superconductivity in trilayer nickelate La${}_4$Ni${}_3$O${}_{10}$
• Superconductivity and normal-state transport in compressively strained La${}_2$PrNi${}_2$O${}_7$ thin films
• Orbital-selective Superconductivity in the Pressurized Bilayer Nickelate La${}_3$Ni${}_2$O${}_7$: An Infinite Projected Entangled-Pair State Study
• Theory of Pressure Dependence of Superconductivity in Bilayer Nickelate La${}_3$Ni${}_2$O${}_7$
• Charge and spin instabilities in superconducting La${}_3$Ni${}_2$O${}_7$
• Bulk superconductivity up to 96 K in pressurized nickelate single crystals
• Density-wave-like gap evolution in La${}_3$Ni${}_2$O${}_7$ under high pressure revealed by ultrafast optical spectroscopy
• Ultrafast Dynamics of Bilayer and Trilayer Nickelate Superconductors
• Resolving the Electronic Ground State of La3Ni2O7-δ Films
• Signature of Superconductivity in Pressurized Trilayer-nickelate Pr${}_4$Ni${}_3$O${}_{10-\delta }$
• Antiferromagnetic Ground State, Charge Density Waves and Oxygen Vacancies Induced Metal-Insulator Transition in Pressurized La${}_3$Ni${}_2$O${}_7$
• Optical properties and electronic correlations in La${}_3$Ni${}_2$O${}_7$ bilayer nickelates under high pressure
• Electronic instability, layer selectivity and Fermi arcs in La${}_3$Ni${}_2$O${}_7$
• The $s^{\pm }$-Wave Superconductivity in the Pressurized La${}_4$Ni${}_3$O${}_{10}$
• Recent progress in nickelate superconductors
• Electronic structure, self-doping, and superconducting instability in the alternating single-layer trilayer stacking nickelates La${}_3$Ni${}_2$O${}_7$
• Bulk superconductivity in pressurized trilayer nickelate Pr4Ni3O10 single crystals
• Sub-nanometer depth resolution and single dopant visualization achieved by tilt-coupled multislice electron ptychography
• Uncovering the Three-Dimensional Structure of Upconverting Core-Shell Nanoparticles with Multislice Electron Ptychography
• Band Structure and Pairing Nature of La${}_3$Ni${}_2$O${}_7$ Thin Film at Ambient Pressure
• Magnetic phase diagram of a two-orbital model for bilayer nickelates varying doping
• Microscopic evidence for spin-spinless stripe order with reduced Ni moments within $ab$ plane for bilayer nickelate La${}_3$Ni${}_2$O${}_7$ probed by ${}^{139}$La-NQR
• Interstitial oxygen order and its competition with superconductivity in La${}_2$PrNi${}_2$O${}_{7+\delta }$
• Imaging the Meissner effect in pressurized bilayer nickelate with integrated multi-parameter quantum sensor
• Decomposition of multilayer superconductivity with interlayer pairing
• Hund's Rule, Interorbital Hybridization, and High-$T_c$ Superconductivity in the Bilayer Nickelate
• PtyRAD: A High-performance and Flexible Ptychographic Reconstruction Framework with Automatic Differentiation
• Collapse of density wave and emergence of superconductivity in pressurized-La${}_4$Ni${}_3$O${}_{10}$ evidenced by ultrafast spectroscopy
• Spin-density wave and superconductivity in La${}_4$Ni${}_3$O${}_{10}$ under ambient pressure
• Impact of Pressure and Apical Oxygen Vacancies on Superconductivity in La${}_3$Ni${}_2$O${}_7$
• Superconducting gap structure and bosonic mode in La2PrNi2O7 thin films at ambient pressure
• DFT+DMFT study of correlated electronic structure in the monolayer-trilayer phase of La${}_3$Ni${}_2$O${}_7$
• Phase diagrams and two key factors to superconductivity of Ruddlesden-Popper nickelates
• Evidence for the Meissner effect in the nickelate superconductor La3Ni2O7-delta single crystal using diamond quantum sensors
• Effective perpendicular electric field as a probe for interlayer pairing in ambient-pressure superconducting La${}_{2.85}$Pr${}_{0.15}$Ni${}_2$O${}_7$ thin films
• Intertwined charge and spin instability of La${}_3$Ni${}_2$O${}_7$
• Ruddlesden-Popper defects act as a free surface: role in formation and photophysical properties of CsPbI3
• First-principles study on Pr-doped Bilayer Nickelate La3Ni2O7
• Highly asymmetric superconducting dome and strange metallicity in La${}_3$Ni${}_2$O${}_7$
• Theoretical study of the crystal structure of the bilayer nickel oxychloride Sr${}_3$Ni${}_2$O${}_5$Cl${}_2$ and analysis of possible unconventional superconductivity
• Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench
• 3D Atomic-Scale Metrology of Strain Relaxation and Roughness in Gate-All-Around (GAA) Transistors via Electron Ptychography
• The electronic structure and disorder effect of La${}_3$Ni${}_2$O${}_7$ superconductor
• Magnetic Correlations and Pairing Tendencies of the Hybrid Stacking Nickelate Superlattice La${}_7$Ni${}_5$O${}_{17}$ (La${}_3$Ni${}_2$O${}_7$/La${}_4$Ni${}_3$O${}_{10}$) under Pressure
• Possible Liquid-Nitrogen-Temperature Superconductivity Driven by Perpendicular Electric Field in the Single-Bilayer Film of La${}_3$Ni${}_2$O${}_7$ at Ambient Pressure
• Origin of the Diagonal Double-Stripe Spin-Density-Wave and Potential Superconductivity in Bulk La${}_3$Ni${}_2$O${}_7$ at Ambient Pressure
• Electronic Structure, Magnetic and Pairing Tendencies of Alternating Single-layer Bilayer Stacking Nickelate La${}_5$Ni${}_3$O${}_{11}$ Under Pressure
• Strain-Engineered Electronic Structure and Superconductivity in La${}_3$Ni${}_2$O${}_7$ Thin Films
• Enhanced superconductivity in the compressively strained bilayer nickelate thin films by pressure
• Complex spin-density-wave ordering in La${}_4$Ni${}_3$O${}_{10}$
• Unifying Strain-driven and Pressure-driven Superconductivity in La${}_3$Ni${}_2$O${}_7$: Suppressed charge/spin density waves and enhanced interlayer coupling
• Unveiling the multiband metallic nature of the normal state in nickelate La3Ni2O7
• Charge distribution and magnetism in bilayer La${}_3$Ni${}_2$O${}_7$: a hybrid functional study
• Theory of potential impurity scattering in pressurized superconducting La${}_3$Ni${}_2$O${}_7$
• Fermi surface reconstruction and enhanced spin fluctuations in strained La${}_3$Ni${}_2$O${}_7$ on LaAlO${}_3$(001) and SrTiO${}_3$(001)
• General trends of electronic structures, superconducting pairing, and magnetic correlations in the Ruddlesden-Popper nickelate $m$-layered superconductors La${}_{m+1}$Ni${}_m$O${}_{3m+1}$
• Variational Quantum Monte Carlo investigations of the superconducting pairing in La${}_3$Ni${}_2$O${}_7$
• Possible Fano effect and suppression of Andreev reflection in La${}_3$Ni${}_2$O${}_7$
• Weakly anisotropic superconductivity of Pr4Ni3O10 single crystals
• Electronic reconstruction and interface engineering of emergent spin fluctuations in compressively strained La${}_3$Ni${}_2$O${}_7$ on SrLaAlO${}_4$(001)
• Advancing atomic electron tomography with neural networks
• Unified mechanism of charge-density-wave and high-$T_c$ superconductivity protected from oxygen vacancies in bilayer nickelates
• Electronic correlations and spin-charge-density stripes in double-layer La${}_3$Ni${}_2$O${}_7$
• Incommensurate spin fluctuations and competing pairing symmetries in La${}_3$Ni${}_2$O${}_7$
• Distinct orbital contributions to electronic and magnetic structures in La${}_4$Ni${}_3$O${}_{10}$
• Orbital-selective electron correlations in high-$T_{\mathrm{c}}$ bilayer nickelates: from a global phase diagram to implications for spectroscopy
• Compressive Strain Turns $s^{\pm }$ into $d$-Wave Pairing in One-unit-cell La${}_3$Ni${}_2$O${}_7$ Thin Film Via Substrate-Induced Hole Doping
• Expanding the trilayer Ruddlesden-Popper nickelate family: Synthesis and characterization of Sm${}_4$Ni${}_3$O${}_{10-\delta }$ single crystals
• The $s\pm$ pairing symmetry in the pressured La${}_3$Ni${}_2$O${}_7$ from electron-phonon coupling
• Effect of doping on the electronic structure, orbital-dependent renormalizations, and magnetic correlations in bilayer La${}_3$Ni${}_2$O${}_7$
• Valency, charge-transfer, and orbital-dependent correlation in bilayer nickelates Nd3Ni2O7
• Pauli-limited upper critical field and anisotropic depairing effect of La2.82Sr0.18Ni2O7 superconducting thin film