Topotactically induced oxygen vacancy order in nickelate single crystals

Abstract

The strong structure-property coupling in rare-earth nickelates has spurred the realization of new quantum phases in rapid succession. Recently, topotactic transformations have provided a new platform for the controlled creation of oxygen vacancies and, therewith, for the exploitation of such coupling in nickelates. Here, we report the emergence of oxygen vacancy ordering in Pr${}_{0.92}$Ca${}_{0.08}$NiO${}_{2.75}$ single crystals obtained via a topotactic reduction of the perovskite phase Pr${}_{0.92}$Ca${}_{0.08}$NiO${}_3$, using CaH${}_2$ as the reducing agent. We unveil a brownmillerite-like ordering pattern of the vacancies by high-resolution scanning transmission electron microscopy, with Ni ions in alternating square-pyramidal and octahedral coordination along the pseudocubic [100] direction. Furthermore, we find that the crystal structure acquires a high level of internal strain, where wavelike modulations of polyhedral tilts and rotations accommodate the large distortions around the vacancy sites. Our results suggest that atomic-resolution electron microscopy is a powerful method to locally resolve unconventional crystal structures that result from the topotactic transformation of complex oxide materials.

arXiv comment9 pages, 4 figures

References in corpus (27)

• Dimensionality Control of Electronic Phase Transitions in Nickel-Oxide Superlattices
• Superconducting Dome in Nd${}_{1-x}$Sr${}_x$NiO${}_2$ Infinite Layer Films
• Phase diagram and superconducting dome of infinite-layer $\mathrm{N}{\mathrm{d}}_{1-\mathrm{x}}\mathrm{S}{\mathrm{r}}_{\mathrm{x}}\mathrm{Ni}{\mathrm{O}}_2$ thin films
• Physics of ultrathin films and heterostructures of rare earth nickelates
• A superconducting praseodymium nickelate with infinite layer structure
• Nickelate superconductivity without rare-earth magnetism: (La,Sr)NiO${}_2$
• Charge disproportionation without charge transfer in the rare-earth nickelates as a possible mechanism for the metal-insulator transition
• Superconductivity in infinite-layer nickelate La${}_{1-x}$Ca${}_x$NiO${}_2$ thin films
• Similarities and differences between infinite-layer nickelates and cuprates and implications for superconductivity
• Doping evolution of the Mott-Hubbard landscape in infinite-layer nickelates
• Two superconducting components with different symmetries in Nd1-xSrxNiO2 films
• Asymmetric orbital-lattice interactions in ultra-thin correlated oxide films
• Structurally Triggered Metal-Insulator Transition in Rare-Earth Nickelates
• Absence of superconductivity in bulk Nd${}_{1-x}$Sr${}_x$NiO${}_2$
• Synthesis and characterization of bulk Nd1-xSrxNiO2 and Nd1-xSrxNiO3
• Tunable Charge and Spin Order in PrNiO${}_3$ Thin Films and Superlattices
• Orbital and Spin Character of Doped Carriers in Infinite-Layer Nickelates
• Neutron diffraction study of spin and charge ordering in SrFeO(3-delta)
• Electronic Structure Trends Across the Rare-Earth Series in Superconducting Infinite Layer Nickelates
• Topotactic transformation of single-crystals: from perovskite to infinite-layer nickelates
• Complex magnetic order in nickelate slabs
• Quantitative determination of bond order and lattice distortions in nickel oxide heterostructures by resonant x-ray scattering
• Orbital engineering in nickelate heterostructures driven by anisotropic oxygen hybridization rather than orbital energy levels
• Oxygen vacancy induced site-selective mott transition in lanio3
• Synthesis and physical properties of LaNiO${}_2$ crystals
• High pO2 Floating Zone Crystal Growth of the Perovskite Nickelate PrNiO3
• Control of the metal-insulator transition in NdNiO${}_3$ thin films through the interplay between structural and electronic properties

Cited by in corpus (5)

• Absence of $3a_0$ Charge Density Wave Order in the Infinite Layer Nickelates
• Synthesis of thin film infinite-layer nickelates by atomic hydrogen reduction: clarifying the role of the capping layer
• Phase formation in hole- and electron-doped rare-earth nickelate single crystals
• Investigation of spin excitations and charge order in bulk crystals of the infinite-layer nickelate LaNiO${}_2$
• Emergent electronic landscapes in a novel valence-ordered nickelate with tri-component nickel coordination