Formal Valence, $d$ Occupation, and Charge-Order Transitions

Abstract

While the formal valence and charge state concepts have been tremendously important in materials physics and chemistry, their very loose connection to actual charge leads to uncertainties in modeling behavior and interpreting data. We point out, taking several transition metal oxides (La${}_2$VCuO${}_6$, YNiO${}_3$, CaFeO${}_3$, AgNiO${}_2$, V${}_4$O${}_7$) as examples, that while dividing the crystal charge into atomic contributions is an ill-posed activity, the 3d occupation of a cation (and more particularly, differences) is readily available in first principles calculations. We discuss these examples, which include distinct charge states and charge-order (or disproportionation) systems, where different "charge states" of cations have identical 3d orbital occupation. Implications for theoretical modeling of such charge states and charge-ordering mechanisms are discussed.

5 pages, 3 figures

References in corpus (4)

• Site-selective Mott transition in rare earth nickelates
• Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2
• Confinement-induced metal-to-insulator transition in strained LaNiO${}_3$/LaAlO${}_3$ superlattices
• Charge disproportionation and collinear magnetic order in the frustrated triangular antiferromagnet AgNiO2

Cited by in corpus (28)

• Reconciling the ionic and covalent pictures in rare-earth nickelates
• Interplay of octahedral rotations and breathing distortions in charge ordering perovskite oxides
• Confinement-driven transitions between topological and Mott phases in (LaNiO3)${}_N$/(LaAlO3)${}_M$(111) superlattices
• Mott Transition and Magnetism in Rare Earth Nickelates and its Fingerprint on the X-ray Scattering
• Charge ordering in Ni${}^{1+}$/Ni${}^{2+}$ nickelates: La${}_4$Ni${}_3$O${}_8$ and La${}_3$Ni${}_2$O${}_6$
• Electronic structure of negative charge transfer CaFeO3 across the metal-insulator transition
• Quantitative determination of bond order and lattice distortions in nickel oxide heterostructures by resonant x-ray scattering
• Charge-order-induced ferroelectricity in LaVO${}_3$/SrVO${}_3$ superlattices
• Structural and Correlation Effects in the Itinerant Insulating Antiferromagnetic Perovskite NaOsO3
• Resonant X-Ray Scattering Measurements of a Spatial Modulation of the Cu 3d and O 2p Energies in Stripe-Ordered Cuprate Superconductors
• Review on quasi-2D square planar nickelates
• Interplay between Spin-Orbit Coupling and Strong Correlation Effects: Comparison of Three Osmate Double Perovskites: Ba${}_{2}A$OsO${}_6$ ($A=$Na, Ca, Y)
• Assessing the formation of spin and charge stripes in La${}_3$Ni${}_2$O${}_7$ from first-principles
• Digital modulation of the nickel valence state in a cuprate-nickelate heterostructure
• Uncertainty principle for experimental measurements: Fast versus slow probes
• Valence and Spin fluctuations in Mn-doped ferroelectric BaTiO3
• Material design of indium based compounds: possible candidates for charge, valence, and bond disproportionation and superconductivity
• Charge States of Ions, and Mechanisms of Charge-Ordering Transitions
• Oxygen vacancy formation and electronic reconstruction in strained LaNiO${}_3$ and LaNiO${}_3$/LaAlO${}_3$ superlattices
• Stability of Room Temperature Compensated Half-Metallicity in Cr-based Inverse-Heusler Compounds
• Analysis of charge states in the mixed valent ionic insulator AgO
• Correlation induced emergent charge order in metallic vanadium dioxide
• Electronic Structures and Phonon Spectra in Boronitride Superconductors LaMBN (M= Ni, Pt)
• Understanding the ferromagnetic insulating state in Cr doped VO${}_2$
• Charge ordering at the interface in (LaMnO${}_3$)${}_{2n}$/(SrMnO${}_3$)${}_n$ superlattices as the origin of their insulating state
• Redox chemistry meets semiconductor defect physics
• Bond-Length-Driven Magnetic Transition in Quasi-One-Dimensional CrSb$X_3$ ($X$=S, Se)
• Revisiting the metal-to-metal transition in $2H$-AgNiO${}_2$