Revisiting the metal-to-metal transition in $2H$-AgNiO${}_2$

Abstract

The layered delafossite compound AgNiO${}_2$ with $2H$ stacking symmetry undergoes a structural metal-to-metal transition at $T_{\mathrm{S}}\sim 365$ K. It has been described in the past as a charge-ordering transition, where local $S=1$ spins are formed on part of the Ni sites. By means of first-principles many body calculations, we show that the transition is in fact a site-selective Mott transition on the Ni sublattice with only minor charge differentiation. Key to this finding is the uncovering of ligand-hole physics, rendering a Ni${}^{2+}$ instead of a formal Ni${}^{3+}$ oxidation state, in conjunction with strong local Coulomb repulsions.

arXiv comment4 pages, 4 figures

References in corpus (18)

• TRIQS: A Toolbox for Research on Interacting Quantum Systems
• Ground state oxygen holes and the metal-insulator transition in the negative charge transfer rare-earth nickelates
• TRIQS/CTHYB: A Continuous-Time Quantum Monte Carlo Hybridization Expansion Solver for Quantum Impurity Problems
• Charge disproportionation without charge transfer in the rare-earth nickelates as a possible mechanism for the metal-insulator transition
• Spin and charge ordering in self-doped Mott insulators
• Late transition-metal oxides with infinite-layer structure: Nickelates versus cuprates
• The properties of ultrapure delafossite metals
• Low-energy description of the metal-insulator transition in the rare-earth nickelates
• Coulomb Correlations and the Wigner-Mott Transition
• Approaching finite-temperature phase diagrams of strongly correlated materials: a case study for V2O3
• Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2
• Unconventional aspects of electronic transport in delafossite oxides
• Formal Valence, $d$ Occupation, and Charge-Order Transitions
• Charge disproportionation and collinear magnetic order in the frustrated triangular antiferromagnet AgNiO2
• Interplay of charge-transfer and Mott-Hubbard physics approached by an efficient combination of self-interaction correction and dynamical mean-field theory
• From basic properties to the Mott design of correlated delafossites
• Direct observation of charge order in triangular metallic AgNiO2 by single-crystal resonant X-ray scattering
• Assessing the correlated electronic structure of lanthanum nickelates