Theory of Valence Transition in BiNiO${}_3$

Abstract

Motivated by the colossal negative thermal expansion recently found in BiNiO${}_3$, the valence transition accompanied by the charge transfer between the Bi and Ni sites is theoretically studied. We introduce an effective model for Bi-$6s$ and Ni-$3d$ orbitals with taking into account the valence skipping of Bi cations, and investigate the ground-state and finite-temperature phase diagrams within the mean-field approximation. We find that the valence transition is caused by commensurate locking of the electron filling in each orbital associated with charge and magnetic orderings, and the critical temperature and the nature of the transitions are strongly affected by the relative energy between the Bi and Ni levels and the effective electron-electron interaction in the Bi sites. The obtained phase diagram well explains the temperature- and pressure-driven valence transitions in BiNiO${}_3$ and the systematic variation of valence states for a series of Bi and Pb perovskite oxides.

5 pages, 5 figures

References in corpus (2)

• Madelung Energy of the Valence Skipping Compound BaBiO${}_3$
• Valence changes associated with the metal-insulator transition in Bi${}_{1-x}$La${}_x$NiO${}_3$

Cited by in corpus (10)

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• Unusual Mott transition associated with charge-order melting in BiNiO${}_3$ under pressure
• Quantum paraelectric state and critical behavior in Sn(Pb)${}_2$P${}_2$S(Se)${}_6$ ferroelectrics
• Phase transitions in the Hubbard model for the bismuth nickelate
• Valence skipping, internal doping and site-selective Mott transition in PbCoO${}_3$ under pressure
• Mechanism of intermetallic charge transfer and bond disproportionation in BiNiO${}_3$ and PbNiO${}_3$ revealed by hard x-ray photoemission spectroscopy
• Charge Kondo Effect and Superconductivity in the Falikov-Kimball model with the Pair Hopping
• Robust electronic and tunable magnetic states in Sm${}_2$NiMnO${}_6$ ferromagnetic insulator
• Existence of inter coupled structural, electronic and magnetic states in Sm${}_2$NiMnO${}_6$ double perovskite